GK 400RB III no bias voltage

[lowell]

This amp came in w/ blown output transistors. I replaced all of 'em, driver transistors and ballast resistors included. Fuse doesn't blow anymore but I have no bias voltage. I'm thinking that Q18 bay be bad. Would a shorted Q18 cause 0v bias?

[kvimbo]

Yes, but more likely Q8 (or both), because if Q18 is SC, than at least 0,6 volts should be there.

[Enzo]

Me too. CHeck both those transistors, and check the boas pot for open condition as well.