Audio Technica ATW-14

[bsco]

This unit, a wireless receiver would turn on but that was it......Upon inspection, I noticed that the Power was being dragged down.......Couldn't find anything that was obvious and after much prodding and poking, I decided to remove the voltage regulator and soldered a pin to where the output pin would be....Hooked up a current adjustable power supply and set the voltage for 10V......and hooked up the board.....I then turned up the current slowly while looking for an overheated IC chip.....I slowly kept increasing the current until there was close to 1 amp of draw ( I wouldn't chance going any higher than that)........voltage was down to probably 1V....The problem turned out to be a very small ceramic cap and not an IC chip like I had thought....it had a funny color to it once it was stressed.....As soon as I removed it, the short was gone....checked the cap.....sure enough...it was shorted......and that was the only part that was bad......The cap was on the power supply leg and every pin on all the chips showed a short to ground....and the power rail went all over the board.....It took awhile, but I managed to get it working....maybe this might help somebody out someday.......
Cheers

[g1]

In some of the discussions you may see a reference to "smoking it out", in regard to finding shorts. That is what this refers to, often the bad cap will smoke or pop. Seems to me the terminology is often seen in discussions of Behringer mixer faults.
The caps that are problematic are the little decoupling caps of which there are many. Sometimes as many as a pair per IC (plus and minus supply to ground), so it's easier to "smoke them out" than remove and check every one.

[Enzo]

Not just Behr mixers. Any op amp mixer. Typically a small cap at every IC to each power rail and ground. can be a nightmare to isolate.

When I get a unit like that loading the supply, actually caps are high up my list after first checking diodes.

[bsco]

Glad to see the site is up again..I kept getting a "Database Error" earlier.....and thanks to everybody here on the forum that has taken the time to help me out.....It is much appreciated......