AMB Laboratories DIY Audio

[jft23]

Hello,

i am building a balanced b22, and 3 boards are working fine, but one cant seems to work properly.
i checked the pin positions of the toshiba q1-q4 with my board version and everything else
i have tried to change all the 550/560 except q17,q18
i also tried to change the mosfets q21-q24
at least i can compare the working boards with the problematic one, so here is a data sheet to help you guys to pin point the problem.

[img]<a%20href="http://imgur.com/lfxde"><img%20src="http://i.imgur.com/lfxde.jpg"%20alt=""%20title="Hosted%20by%20imgur.com"%20/></a>[/img]

[amb]

Looks like D1 is defective -- it doesn't have 12V across it.

[jft23]

Yes D1 was the problem, everything is working fine now. I replaced the diode before this post was approved but thanks for the confirmation!