[time-nuts] Re: 5370A repair

[paul swed]

Tom I have seen the caps short and no smoke. There are 2 15V caps C17
before R16 and C16 after. Either could cause the issue. Simply lift a lead
on both caps and see if the system works.
Paul
WB8TSL

On Thu, Jul 17, 2025 at 1:36 PM Tom Verbeure <hombre at gmail.com> wrote:

>
>
> On Thu, Jul 17, 2025 at 10:00 AM paul swed <paulswedb at gmail.com> wrote:
>
>> Tom check to see if the 10 MHz feeds the 100 MHz multiplier. I think that
>> ultimately drives the system.
>> Without the board I think the clocks are missing.
>>
>
> Of course! I should have thought about that.
>
> Right now, I don't even have anything on the "INT" or on the "EXT" test
> points on the A8 reference frequency buffer board. At least that narrows
> the issue down to this board only for now.
>
> I don't see anything obvious on the board where a failure would result in
> shorting the +15V, but one useful thing is that the +15V is only used when
> there's an EXT clock in play. So I could disconnect the +15V (e.g. by
> removing R16 in the ripple filter) and then check if the INT clock comes
> through.
>
> Thanks!
> Tom
>
>