The left channel of my AB100 let the smoke out after about a year of playing in my garage. The day it quit, the temperature was 78 degrres in the garage and the stereo was playing at a moderately high volume level. I heard the left channel quit and went to check it, the left channel was hot.
When I removed the cover, I found the two rail fuses blown. I use 5 amp fuses on the rails. I replaced the two fuses and powered it up and it smoked R16 in the diagram below. See also the picture.
I then checked all the outputs for shorts to ground and to verify they were still good using a meter on diode check.
I then checked R6 and R5, both good.
I then checked T6, T7, T1 and T2, T8, T3, all good. I checked these by removing and checking with a meter on diode check and in a cheap chinese tester.
I also checked C5, it shows high resistance across it and correct capacitance.
It's pretty obvious to me that the issue is in the front end, but so far everything is checking out.
Does anyone see something that I have missed? To smoke that large Vishay resistor I would think something would be very obvious, but I'm not finding anything.
