[time-nuts] Anyone familiar with SR-620 repair?

[SAIDJACK at aol.com]

Here is a trick or two that may work:
 
feed a very small AC voltage with say 1KHz and 10mV into the bad power  
rail. It won't hurt anything.

Then use an old cassette players' magnetic pickup and amplifier to  follow 
the signal to the short. No need for expensive hall effect meters.
 
Another trick that I often use is force-feed power into the bad power rail. 
 If it's a 5V rail, then say 5V at 2A.
 
That can work by having the bad part get hot really quickly, by allowing  
you to DC probe with a millivolt setting, or it can backfire if it's a tant 
cap  by blowing it up. I would use that only as a last resort if the first 
trick  didn't work, as the second trick can be dangerous! So please be 
careful, any  repair should be done only with proper equipment (using a 110V 
isolation  transformer for example)...
 
bye,
Said
 
 
In a message dated 3/23/2012 14:13:57 Pacific Daylight Time,  
jfor at quikus.com writes:

Are  there Hall Effect probes for chasing DC faults?

I'm very familiar with  the HP Logic Current Tracer, but AFAIK that is only
sensitive to fast  pulses, from the Logic Pulser for example.

The threashold is  adjustable, so maybe it will sense DC currents.

If it is DC sensitive  it'd be even more wonderful. I'll try it after  
dinner.

Thanks,

-John