adcom 5500 channel failure


2016-03-19 3:25 pm
Hello everyone. I just joined and my name is Eric. This site looks pretty interesting. Lots of info here. Well I have an Adcom 5500 that has a dead channel. IT just made a sharp crackle noise through the speaker and it was over. No sound at all. The remaining channel sounds good as it always did. I tested the ps and its fine. Desolderd the 8 ,1000uf 100v caps and tested with a cap tester and they are testing strong. So now im at the point that I have removed the bad channels driver board. Im thinking that is where the problem exists. I have the schematic and in my researches ive read that the thermal breaker (tb 101) could be cooked and causing ol but its not. I tested it on the board and I dont know it it makes a difference but I got continuity with a dmm. Well im wondering if there are common problems with these boards if indeed it is the driver board. The irfp 9240 and 240's are suspect but before I desolder them to test them are there other things I should investigate before I get into that? All fuses test good too. This amp was built in 94 I dunno if that helps but im putting it in. So im the proverbial blind squirrel trying to find a nut. Any insight would be greatly appreciated. Thanks Eric G.