[Kenwood] TL-922A blowing fuses

[Roger Shultz]

I (often reluctantly like in this case) do some part time work for a local
radio shop that took in a TL-922A from a customer. 

The first complaint was that there was a cap underneath that had arced and
left a small burn mark on the chassis thought by the shop owner to be a
"simple fix". Indeed it was obvious that the cap had arced and was showing
leakage. The cap, a 220 dipped mica, was easily replaced.

The second part was the fuse blowing complaint. I had no information
supplied about anything wrong except the cap though I didn't think a leaky
cap could cause fuses to blow. The cap was not the result of the fuse
blowing.  As soon as power was turned on, both fuses immediately blew
accompanied by a slight smell, you know the one. Nothing is visibly burned.

I've rechecked the caps and all are good, I've checked the 3-500's with a
VOM and they show good filament and no shorts, though I've read that is not
the end all to assure they are OK. I made sure the interlock was not
grounded when I took off the cover. I checked a couple filters that I could
reach and they still look like caps. 

I have not gotten to test the diode string because I have yet to figure out
how to remove it to get access. 

At $7.50 per fuse, I would really like to have some sort of idea of what I'm
chasing and be able to check it before attempting to put power to it.
Clearly without a cause and repair, it's just going to do it again.

Naturally, dealing with a HV supply is dangerous so I am being very
cautious. Any suggestions of common failures that resemble what I've
described?

73, Roger, NJ2R