Yikes! Spark when powered up!

[sinnerboy]

Fired up my KA-701 this morning and a saw a spark in the rear right corner. The speaker relay kicked in, everything seems to be working (played cd thru Aux). I removed the cover, didn't see any flash marks or discoloration. It hasn't done it since.
The situation around this was that yesterday I had it sitting on the back bumpers while I worked on the power switch (trying to fix the broken bat, referred to in another thread). Nothing was done to the inside components, it may be a coincidence that it happened after having the cover off (?). A little unnerving and I'm not sure what to expect now. Like I said, it seems to be working normally since the spark, and hasn't repeated itself as of yet. Any idea what could have happened? TIA

 

[gort69]

Never been inside one of those - but unplug the amp ang follow the wires from the power switch and see if one connects to a wire wrap post on a PCB. If so, take a good look at where the pin is soldered to the board and check for a cracked solder joint.

 

[transmaster]

Feel lucky you are not working on Ten Tec Amateur radio gear. Neutralized the carrier on my Omni Vl. It was throwing a carriers on it’s side bands. It was working OK. Put the covers back on keyed it up and it wouldn’t transmit ??? Took the covers off to check it out and started working ???? Put the covers back on and it is OK. A complete mystery, the Omni VI 563 is a steaming pile so I should not be surprised.