I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
Message: 1
Date: Wed, 8 Apr 2020 13:23:17 -0400
From: Rick Bale rpbale@bellsouth.net
To: volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
CAD2Mu-MeQOkcSHn2LjJ4aKO1wHtEuyK2MDjuRG51pyhmSGNQ0A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Thank you David that is good information. This is good news is I have the
correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has
programmed up a new set of PROM's plus I have the old ones.
I'll reassemble the unit after doing an alcohol scrub down on all the
boards because there evidence of water damage on the top cover's shield.
It's turned the shield green and has a mildew smell. Joe saw some corrosion
on the old PROMs too. In the long run I'll need to replace the cover's
inside shield. I should be able order a custom one from a PCB shop as it's
just a large un-etched tin coated PCB board.
If the cleaning doesn't work then it seems like I need to find a test point
to monitor the boot up data stream. Does that seem like a good place
to start since power rails are good? Is it best to watch it from the GPIB
connection?
Rick
Message: 2
Date: Wed, 8 Apr 2020 14:17:52 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 000d01d60da8$1ca94350$55fbc9f0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
Message: 3
Date: Wed, 8 Apr 2020 14:29:09 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 001b01d60da9$b0094540$101bcfc0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
Grrr why was my link split across two lines - it was sent as one line ...
Be warned you'll need to re-constitute the link ...
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
David
C. Partridge
Sent: 08 April 2020 14:18
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Message: 4
Date: Wed, 8 Apr 2020 13:33:48 +0000
From: Shaun Merrigan shaun_merrigan@outlook.com
To: Discussion of precise voltage measurement
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
Content-Type: text/plain; charset="Windows-1252"
Rick,
I have two 7081?s with the relevant configuration as follows:
S\N 1395 with board 70817514 and 2764 ROMS
S\N 415 with board 70817504 and 2564 ROMS
I can also confirm that swapping ROMS between the board revisions does
not
work.
Hope this helps.
Shaun Merrigan
https://www.shaunmerrigan.info
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of David C.
Partridge david.partridge@perdrix.co.uk
Sent: Wednesday, April 8, 2020 7:17:52 AM
To: 'Discussion of precise voltage measurement' <
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Subject: Digest Footer
volt-nuts mailing list
volt-nuts@lists.febo.com
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 1
Subject: Digest Footer
volt-nuts mailing list
volt-nuts@lists.febo.com
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 2
Be warned that IIRC the orientation of the ICs on the earthy CPU board isn't
consistent - pay careful attention to the markings on the silkscreen
Also the order in which the EPROMs are installed isn't exactly what you
might expect ... Check most carefully
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of Rick
Bale
Sent: 20 April 2020 19:32
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
David, I picked up on the eproms placement and went by the silkscreen
rather than the manual. I'll double check the RAM right now.
I just finished checking the signal on the IC10/11. The signal between
pins 2 & 3 are a solid 5v high on both IC10/11.
Rick
On Mon, Apr 20, 2020 at 3:25 PM David C. Partridge <
david.partridge@perdrix.co.uk> wrote:
Be warned that IIRC the orientation of the ICs on the earthy CPU board
isn't
consistent - pay careful attention to the markings on the silkscreen
Also the order in which the EPROMs are installed isn't exactly what you
might expect ... Check most carefully
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 20 April 2020 19:32
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
David,
We're good on the placement of the RAM. On this Earthy Processor board's
silkscreen all installed IC's have pin 1 oriented towards the front panel.
Rick
On Mon, Apr 20, 2020 at 3:25 PM David C. Partridge <
david.partridge@perdrix.co.uk> wrote:
Be warned that IIRC the orientation of the ICs on the earthy CPU board
isn't
consistent - pay careful attention to the markings on the silkscreen
Also the order in which the EPROMs are installed isn't exactly what you
might expect ... Check most carefully
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 20 April 2020 19:32
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Rick,
Maybe not the solution to your particular problem but for $5.00 (on
AliExpress) or $10 (on Amazon) you can get an amazingly useful 25 MHz, 8
channel logic analyzer.
You can use it with sigrok, free software that comes with a large number of
protocol decoders.
I just got one and I have used it quite a bit in the last couple of months
to troubleshoot serial data issues with a UART and I2C issues that would
have been extremely hard or impossible with my digital storage oscilloscope.
It's not a replacement for a scope but a very useful complement and far and
away the best $5 I have ever spent on anything.
It may not be useful when troubleshooting buses wider than 8 bits or faster
than a few MHz but everyone should have one of those.
For a few $ more, they do have faster, 16 bit models.
Didier KO4BB
On Mon, Apr 20, 2020, 1:33 PM Rick Bale rpbale@bellsouth.net wrote:
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
Message: 1
Date: Wed, 8 Apr 2020 13:23:17 -0400
From: Rick Bale rpbale@bellsouth.net
To: volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
CAD2Mu-MeQOkcSHn2LjJ4aKO1wHtEuyK2MDjuRG51pyhmSGNQ0A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Thank you David that is good information. This is good news is I have
the
correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has
programmed up a new set of PROM's plus I have the old ones.
I'll reassemble the unit after doing an alcohol scrub down on all the
boards because there evidence of water damage on the top cover's shield.
It's turned the shield green and has a mildew smell. Joe saw some
corrosion
on the old PROMs too. In the long run I'll need to replace the cover's
inside shield. I should be able order a custom one from a PCB shop as
it's
just a large un-etched tin coated PCB board.
If the cleaning doesn't work then it seems like I need to find a test
point
to monitor the boot up data stream. Does that seem like a good place
to start since power rails are good? Is it best to watch it from the GPIB
connection?
Rick
Message: 2
Date: Wed, 8 Apr 2020 14:17:52 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 000d01d60da8$1ca94350$55fbc9f0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
Message: 3
Date: Wed, 8 Apr 2020 14:29:09 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 001b01d60da9$b0094540$101bcfc0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
Grrr why was my link split across two lines - it was sent as one line
...
Be warned you'll need to re-constitute the link ...
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
David
C. Partridge
Sent: 08 April 2020 14:18
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Message: 4
Date: Wed, 8 Apr 2020 13:33:48 +0000
From: Shaun Merrigan shaun_merrigan@outlook.com
To: Discussion of precise voltage measurement
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
Content-Type: text/plain; charset="Windows-1252"
Rick,
I have two 7081?s with the relevant configuration as follows:
S\N 1395 with board 70817514 and 2764 ROMS
S\N 415 with board 70817504 and 2564 ROMS
I can also confirm that swapping ROMS between the board revisions does
not
work.
Hope this helps.
Shaun Merrigan
https://www.shaunmerrigan.info
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of David
C.
Partridge david.partridge@perdrix.co.uk
Sent: Wednesday, April 8, 2020 7:17:52 AM
To: 'Discussion of precise voltage measurement' <
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Subject: Digest Footer
volt-nuts mailing list
volt-nuts@lists.febo.com
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 1
Subject: Digest Footer
volt-nuts mailing list
volt-nuts@lists.febo.com
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 2
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Dedier,
I will definitely check into that. What model did you buy?
Rick
Rick
Sent from iPhone.
On Apr 20, 2020, at 6:24 PM, Didier Juges shalimr9@gmail.com wrote:
Rick,
Maybe not the solution to your particular problem but for $5.00 (on
AliExpress) or $10 (on Amazon) you can get an amazingly useful 25 MHz, 8
channel logic analyzer.
You can use it with sigrok, free software that comes with a large number of
protocol decoders.
I just got one and I have used it quite a bit in the last couple of months
to troubleshoot serial data issues with a UART and I2C issues that would
have been extremely hard or impossible with my digital storage oscilloscope.
It's not a replacement for a scope but a very useful complement and far and
away the best $5 I have ever spent on anything.
It may not be useful when troubleshooting buses wider than 8 bits or faster
than a few MHz but everyone should have one of those.
For a few $ more, they do have faster, 16 bit models.
Didier KO4BB
On Mon, Apr 20, 2020, 1:33 PM Rick Bale rpbale@bellsouth.net wrote:
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I should
move the conversation to the Solartron Group?
Thanks, Rick
Message: 1
Date: Wed, 8 Apr 2020 13:23:17 -0400
From: Rick Bale rpbale@bellsouth.net
To: volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
CAD2Mu-MeQOkcSHn2LjJ4aKO1wHtEuyK2MDjuRG51pyhmSGNQ0A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Thank you David that is good information. This is good news is I have
the
correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has
programmed up a new set of PROM's plus I have the old ones.
I'll reassemble the unit after doing an alcohol scrub down on all the
boards because there evidence of water damage on the top cover's shield.
It's turned the shield green and has a mildew smell. Joe saw some
corrosion
on the old PROMs too. In the long run I'll need to replace the cover's
inside shield. I should be able order a custom one from a PCB shop as
it's
just a large un-etched tin coated PCB board.
If the cleaning doesn't work then it seems like I need to find a test
point
to monitor the boot up data stream. Does that seem like a good place
to start since power rails are good? Is it best to watch it from the GPIB
connection?
Rick
Message: 2
Date: Wed, 8 Apr 2020 14:17:52 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 000d01d60da8$1ca94350$55fbc9f0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
Message: 3
Date: Wed, 8 Apr 2020 14:29:09 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 001b01d60da9$b0094540$101bcfc0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
Grrr why was my link split across two lines - it was sent as one line
...
Be warned you'll need to re-constitute the link ...
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
David
C. Partridge
Sent: 08 April 2020 14:18
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Message: 4
Date: Wed, 8 Apr 2020 13:33:48 +0000
From: Shaun Merrigan shaun_merrigan@outlook.com
To: Discussion of precise voltage measurement
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
Content-Type: text/plain; charset="Windows-1252"
Rick,
I have two 7081?s with the relevant configuration as follows:
S\N 1395 with board 70817514 and 2764 ROMS
S\N 415 with board 70817504 and 2564 ROMS
I can also confirm that swapping ROMS between the board revisions does
not
work.
Hope this helps.
Shaun Merrigan
https://www.shaunmerrigan.info
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of David
C.
Partridge david.partridge@perdrix.co.uk
Sent: Wednesday, April 8, 2020 7:17:52 AM
To: 'Discussion of precise voltage measurement' <
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514) earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Subject: Digest Footer
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http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 1
Subject: Digest Footer
volt-nuts mailing list
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End of volt-nuts Digest, Vol 125, Issue 2
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To unsubscribe, go to
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volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
I've order a few tools to make this more fun and less tedious. I should
have the following items next week.
Inno-Maker LA2016 USB logic analyzer
40-pin chip clip
24-pin chip clip
While I'm waiting for these I've been studying how the logic work from the
service manual. There's a lot of revealing info in there. Since I have
several more days until they arrive I will take some time to check if the
display is receiving any instructions. It would be a shame if the VFD was
simply dead in addition to all the LEDs being stuck on.
Rick
On Mon, Apr 20, 2020 at 6:24 PM Didier Juges shalimr9@gmail.com wrote:
Rick,
Maybe not the solution to your particular problem but for $5.00 (on
AliExpress) or $10 (on Amazon) you can get an amazingly useful 25 MHz, 8
channel logic analyzer.
You can use it with sigrok, free software that comes with a large number of
protocol decoders.
I just got one and I have used it quite a bit in the last couple of months
to troubleshoot serial data issues with a UART and I2C issues that would
have been extremely hard or impossible with my digital storage
oscilloscope.
It's not a replacement for a scope but a very useful complement and far and
away the best $5 I have ever spent on anything.
It may not be useful when troubleshooting buses wider than 8 bits or faster
than a few MHz but everyone should have one of those.
For a few $ more, they do have faster, 16 bit models.
Didier KO4BB
On Mon, Apr 20, 2020, 1:33 PM Rick Bale rpbale@bellsouth.net wrote:
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to swap.
So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is
all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power rails.
I corrected this by replacing C56, C57, C58 filter caps. They all
measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen. I
feel like I need to check the data during boot up. Probably means
decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It
would
seem reasonable that they would all come on during boot up or on a reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I
should
move the conversation to the Solartron Group?
Thanks, Rick
Message: 1
Date: Wed, 8 Apr 2020 13:23:17 -0400
From: Rick Bale rpbale@bellsouth.net
To: volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
CAD2Mu-MeQOkcSHn2LjJ4aKO1wHtEuyK2MDjuRG51pyhmSGNQ0A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Thank you David that is good information. This is good news is I have
the
correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has
programmed up a new set of PROM's plus I have the old ones.
I'll reassemble the unit after doing an alcohol scrub down on all the
boards because there evidence of water damage on the top cover's
shield.
It's turned the shield green and has a mildew smell. Joe saw some
corrosion
on the old PROMs too. In the long run I'll need to replace the cover's
inside shield. I should be able order a custom one from a PCB shop as
it's
just a large un-etched tin coated PCB board.
If the cleaning doesn't work then it seems like I need to find a test
point
to monitor the boot up data stream. Does that seem like a good place
to start since power rails are good? Is it best to watch it from the
GPIB
connection?
Rick
Message: 2
Date: Wed, 8 Apr 2020 14:17:52 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 000d01d60da8$1ca94350$55fbc9f0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf
Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
Message: 3
Date: Wed, 8 Apr 2020 14:29:09 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 001b01d60da9$b0094540$101bcfc0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
Grrr why was my link split across two lines - it was sent as one line
...
Be warned you'll need to re-constitute the link ...
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf
Of
David
C. Partridge
Sent: 08 April 2020 14:18
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf
Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Message: 4
Date: Wed, 8 Apr 2020 13:33:48 +0000
From: Shaun Merrigan shaun_merrigan@outlook.com
To: Discussion of precise voltage measurement
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
Content-Type: text/plain; charset="Windows-1252"
Rick,
I have two 7081?s with the relevant configuration as follows:
S\N 1395 with board 70817514 and 2764 ROMS
S\N 415 with board 70817504 and 2564 ROMS
I can also confirm that swapping ROMS between the board revisions
does
not
work.
Hope this helps.
Shaun Merrigan
https://www.shaunmerrigan.info
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of
David
C.
Partridge david.partridge@perdrix.co.uk
Sent: Wednesday, April 8, 2020 7:17:52 AM
To: 'Discussion of precise voltage measurement' <
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On Behalf
Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Subject: Digest Footer
volt-nuts mailing list
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http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 1
Subject: Digest Footer
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End of volt-nuts Digest, Vol 125, Issue 2
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To unsubscribe, go to
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volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
Using the new logic analyzer and can see that the CPU appears to be
working. It comes out of reset 200ms after receiving it's VCC signal. And
there is data on the address and data busses. Clock signals are there. But
it's still very difficult to understand the data I'm seeing and where to
look. I keep thinking about the display that's off entirely. I need to
know if the VFD is dead. I'm not sure how to test it. I did recheck the
floating power rails and noticed some ripple on the -28V rail. It was also
only about -27V. I check it's filter cap and sure enough one of the caps
was open. Easy fix.
Does any one have any advice on how to verify a bad VFD without just
replacing it? The face plate is a work of art. I don't want to
disassemble the board as getting the LED in line again looks tedious. The
VFD is getting it's +40v, +5v and 0v. Should I expect to see something on
one spot of the VFD when it's powered up, or do I need to drive some logic
HI or LO into it?
Thanks
Rick
On Tue, Apr 28, 2020 at 12:33 PM Rick Bale rpbale@gmail.com wrote:
I've order a few tools to make this more fun and less tedious. I should
have the following items next week.
Inno-Maker LA2016 USB logic analyzer
40-pin chip clip
24-pin chip clip
While I'm waiting for these I've been studying how the logic work from the
service manual. There's a lot of revealing info in there. Since I have
several more days until they arrive I will take some time to check if the
display is receiving any instructions. It would be a shame if the VFD was
simply dead in addition to all the LEDs being stuck on.
Rick
On Mon, Apr 20, 2020 at 6:24 PM Didier Juges shalimr9@gmail.com wrote:
Rick,
Maybe not the solution to your particular problem but for $5.00 (on
AliExpress) or $10 (on Amazon) you can get an amazingly useful 25 MHz, 8
channel logic analyzer.
You can use it with sigrok, free software that comes with a large number
of
protocol decoders.
I just got one and I have used it quite a bit in the last couple of months
to troubleshoot serial data issues with a UART and I2C issues that would
have been extremely hard or impossible with my digital storage
oscilloscope.
It's not a replacement for a scope but a very useful complement and far
and
away the best $5 I have ever spent on anything.
It may not be useful when troubleshooting buses wider than 8 bits or
faster
than a few MHz but everyone should have one of those.
For a few $ more, they do have faster, 16 bit models.
Didier KO4BB
On Mon, Apr 20, 2020, 1:33 PM Rick Bale rpbale@bellsouth.net wrote:
I's been a while since I last posted on my 7081. I needed to wait to
receive new earthy CPU and DMA chips. They are cheap and easy to
swap. So
far, with Joe's help, I've replaced the earthy side PROMS. Also new is
all
the RAM, DMA and microprocessor. I also went back and rechecked all the
power rails. I found a little extra noise on the +5v & +40v power
rails.
I corrected this by replacing C56, C57, C58 filter caps. They all
measured
about 50% or less of their original uF. The 12v filter C59 was okay.
I have the same symptom of all LED stuck on and nothing on the screen.
I
feel like I need to check the data during boot up. Probably means
decoding
the logic. Maybe it's hung on a reset since all the LEDs are on. It
would
seem reasonable that they would all come on during boot up or on a
reset.
The problem is I don't have a logic analyzer or probe but mainly don't
really know where to start in the circuit.
Does anyone have any suggestions on where to start. Do you think I
should
move the conversation to the Solartron Group?
Thanks, Rick
Message: 1
Date: Wed, 8 Apr 2020 13:23:17 -0400
From: Rick Bale rpbale@bellsouth.net
To: volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
CAD2Mu-MeQOkcSHn2LjJ4aKO1wHtEuyK2MDjuRG51pyhmSGNQ0A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Thank you David that is good information. This is good news is I have
the
correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has
programmed up a new set of PROM's plus I have the old ones.
I'll reassemble the unit after doing an alcohol scrub down on all the
boards because there evidence of water damage on the top cover's
shield.
It's turned the shield green and has a mildew smell. Joe saw some
corrosion
on the old PROMs too. In the long run I'll need to replace the
cover's
inside shield. I should be able order a custom one from a PCB shop as
it's
just a large un-etched tin coated PCB board.
If the cleaning doesn't work then it seems like I need to find a test
point
to monitor the boot up data stream. Does that seem like a good place
to start since power rails are good? Is it best to watch it from the
GPIB
connection?
Rick
Message: 2
Date: Wed, 8 Apr 2020 14:17:52 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 000d01d60da8$1ca94350$55fbc9f0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On
Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
Message: 3
Date: Wed, 8 Apr 2020 14:29:09 +0100
From: "David C. Partridge" david.partridge@perdrix.co.uk
To: "'Discussion of precise voltage measurement'"
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID: 001b01d60da9$b0094540$101bcfc0$@perdrix.co.uk
Content-Type: text/plain; charset="us-ascii"
Grrr why was my link split across two lines - it was sent as one
line
...
Be warned you'll need to re-constitute the link ...
David
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On
Behalf Of
David
C. Partridge
Sent: 08 April 2020 14:18
To: 'Discussion of precise voltage measurement'
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On
Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Message: 4
Date: Wed, 8 Apr 2020 13:33:48 +0000
From: Shaun Merrigan shaun_merrigan@outlook.com
To: Discussion of precise voltage measurement
volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] Solartron 7081
Message-ID:
<
Content-Type: text/plain; charset="Windows-1252"
Rick,
I have two 7081?s with the relevant configuration as follows:
S\N 1395 with board 70817514 and 2764 ROMS
S\N 415 with board 70817504 and 2564 ROMS
I can also confirm that swapping ROMS between the board revisions
does
not
work.
Hope this helps.
Shaun Merrigan
https://www.shaunmerrigan.info
From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of
David
C.
Partridge david.partridge@perdrix.co.uk
Sent: Wednesday, April 8, 2020 7:17:52 AM
To: 'Discussion of precise voltage measurement' <
Subject: Re: [volt-nuts] Solartron 7081
There is a downloadable high quality scan of the Service Manual
which I
produced a while ago, that you can download from here:
<
%20and%207081
<
It has the schematics for both the early (7504) and late (7514)
earthy
processor boards, and contains numerous corrections to the text and
parts
lists. The schematics have been cleaned up and corrected where
necessary.
You can tell which ROMS the earthy processor uses based on the board
number:
Board 70817504 uses 2564s while 70817514 uses 2764s.
If you use the wrong ROMs - it won't work!
The Test Spec document is also of interest.
Keep well
D
-----Original Message-----
From: volt-nuts [mailto:volt-nuts-bounces@lists.febo.com] On
Behalf Of
Rick
Bale
Sent: 08 April 2020 13:45
To: volt-nuts@lists.febo.com
Subject: [volt-nuts] Solartron 7081
All,
Here's an update on my 7081 that hangs during boot up
volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.
Subject: Digest Footer
volt-nuts mailing list
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http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
End of volt-nuts Digest, Vol 125, Issue 1
Subject: Digest Footer
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End of volt-nuts Digest, Vol 125, Issue 2
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To unsubscribe, go to
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volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to
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and follow the instructions there.
This is a long-shot, but try looking at your VFD with a digital camera
(cell phone). Most digital cameras can see near infrared. If you can
see the filament glowing then you know the filament is intact. If not,
you don't know for sure. You would then have to measure the filament
current somehow.
Brent
On 5/4/2020 7:20 PM, Rick Bale wrote:
Using the new logic analyzer and can see that the CPU appears to be
working. It comes out of reset 200ms after receiving it's VCC signal. And
there is data on the address and data busses. Clock signals are there. But
it's still very difficult to understand the data I'm seeing and where to
look. I keep thinking about the display that's off entirely. I need to
know if the VFD is dead. I'm not sure how to test it. I did recheck the
floating power rails and noticed some ripple on the -28V rail. It was also
only about -27V. I check it's filter cap and sure enough one of the caps
was open. Easy fix.
Does any one have any advice on how to verify a bad VFD without just
replacing it? The face plate is a work of art. I don't want to
disassemble the board as getting the LED in line again looks tedious. The
VFD is getting it's +40v, +5v and 0v. Should I expect to see something on
one spot of the VFD when it's powered up, or do I need to drive some logic
HI or LO into it?
Thanks
Rick
Brent, I check that our tomorrow. Thanks
Rick
On Mon, May 4, 2020 at 9:36 PM Brent Gordon volt-nuts@adobe-labs.com
wrote:
This is a long-shot, but try looking at your VFD with a digital camera
(cell phone). Most digital cameras can see near infrared. If you can
see the filament glowing then you know the filament is intact. If not,
you don't know for sure. You would then have to measure the filament
current somehow.
Brent
On 5/4/2020 7:20 PM, Rick Bale wrote:
Using the new logic analyzer and can see that the CPU appears to be
working. It comes out of reset 200ms after receiving it's VCC signal.
And
there is data on the address and data busses. Clock signals are there.
But
it's still very difficult to understand the data I'm seeing and where to
look. I keep thinking about the display that's off entirely. I need to
know if the VFD is dead. I'm not sure how to test it. I did recheck the
floating power rails and noticed some ripple on the -28V rail. It was
also
only about -27V. I check it's filter cap and sure enough one of the caps
was open. Easy fix.
Does any one have any advice on how to verify a bad VFD without just
replacing it? The face plate is a work of art. I don't want to
disassemble the board as getting the LED in line again looks tedious.
The
VFD is getting it's +40v, +5v and 0v. Should I expect to see something
on
one spot of the VFD when it's powered up, or do I need to drive some
logic
HI or LO into it?
Thanks
Rick