K8060 problem

I have built 6 pcs. of K8060 and put them in a enclosure for my home theatre equipment. 5 amplifiers works fine, but i have a problem with one.

Bulbtest and bias adjust is ok, everything looks ok but i have -40VDC on speaker output.

Yesterday i replaced all transistors, still got -40VDC. It seems that power supply part is ok and as far as i can see solderings are ok. I havent replaced any diod:s or caps/resistors.

Anyone?

As you have 5 others that work fine, it is easy to compare voltages at different points in the circuit. Start with power supply, work towards the power transistors. Measure with respect to ground.