[time-nuts] Tbolt failure modes

Magnus Danielson magnus at rubidium.dyndns.org
Tue May 8 22:41:02 UTC 2012


On 05/09/2012 12:23 AM, bg at lysator.liu.se wrote:
> Hi Bob,
>
> The DB-9 looks fine even with magnifying glass.
> The good one has a MAX232EWE IC, the faulty has a TC232EOE. I see
> RS232-level coming in at pin 13 and going inside the Tbolt at pin 12 (ttl
> level).So there should be no problem there.
>
> Have also swapped PSU board, so the problem is inside the actual GPSDO board.

If you now have opened them up, try A/B check pins for clocks etc.

I'd check if the clock works, internal powers works and that the reset 
has been released. The easy basic stuff.

> The 232 level IC is a dual channel RX/TX translator. Anyone know what the
> second 232 port is used for?

Trace the leads and see if there is hand-shake signal on the DB-9 
(likely) or if it in fact is a second serial port (less likely).

Cheers,
Magnus




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