KRK V8 Studio Monitor Repair!

[angelothewolf]

OK, +/-15V supplies are OK. I got 7.5mV on U2 pin1 and 2.6mV on pin7. the rest of the opamps are below 2mV dc on pins 1 & 7...

[diydidi]

I hate to say it but you've got a tough dog here with this repair.
Ok. Next step: are the feedback resistors on Lm3886's good and are the trax linking these intact?

[angelothewolf]

Yeah, already check those. Im getting crazy with this sh.. the only reason can be the 3886 isnt it? what doesnt fit in my head is that i have the same problem before with the original 3886s.

got the two boards on the bench, the good one and the broken one. measuring resistance betwen V+ and Output (3886) i get 50Meg on the good one and 4Meg on the broken one. Intresting... but how the ff.. i get 40 VDC on the outputs????? any ideas??

[diydidi]

Got to be lm3886's

[Mrsices]

Two of your 3886s are in parallel, so if one is bad.