[time-nuts] Normal operating specs of a Morion MV89?

Brian M brayniac at gmail.com
Tue Sep 20 16:06:59 EDT 2016


Yes. This low output due to capacitor failure is a very common failure.
>From the last set of MV89a I got on the bay, all had this issue.

I had good luck opening mine with a hot air rework station with a small
nozzle to blow the solder seal away. A bit of careful prying with a thin
flat screwdriver while it is still hot to pop the bottom from the case. The
capacitor is easy to get to once the outer can is removed. Hot air to
remove. Then tweezers and a fine point soldering pencil made for an easy
repair.

Obviously, be very careful and be sure to work on an appropriate surface
for the amount of heat involved.
- Brian

On Tue, Sep 20, 2016, 12:57 PM Bryan _ <bpl521 at outlook.com> wrote:

> May also want to check the output amplitude. If memory serves me correct
> it is very common for a capacitor inside this model number to fail. It can
> be fixed but requires a torch or a pretty heavy duty soldering iron to get
> the can open.
> http://www.rbarrios.com/projects/MV89A/
>
> -=Bryan=-
>
> > From: listertim at gmail.com
> > Date: Mon, 19 Sep 2016 14:31:06 -0700
> > To: time-nuts at febo.com
> > Subject: [time-nuts] Normal operating specs of a Morion MV89?
> >
> > I recently ordered and received what claims to be a 2007 vintage
> > Morion MV89 from ebay (I say claimed as that what the auction item
> > said, but my unit is missing the identifying label on the top and just
> > has '2007 MV89A' written on the side in marker). I've powered it up
> > with a bench power supply at 12V and it's drawing 390mA at steady
> > state. I measured the case temperature with a ThermaPen Mk4 (not often
> > I get to combine the hobbies of bbq and timenuts...) which is
> > calibrated to +/-0.7F to be about 111F, varying somewhat with
> > position.
> >
> > This seems pretty hot - Is this normal ? The datasheet says it should
> > draw <350mA when at steady state but doesn't say what temp it should
> > be at. Does anyone else have info on their version to see whether this
> > is normal ?
> >
> > Cheers,
> > Tim
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