Hi to everyone we are working on a Powerbass atm-440.2 car amp, and the output transistors were shorted on channel one. New outputs fixed channel one, but channel two has +28 volts at the speaker line. We have replaced the output transistors , the drivers, and have checked five chip transistors ( diode check ) with nothing that looks shorted. We have checked chip resistors, chip doides and caps ( in circuit ) with nothing looking bad! We were wondering if anyone had a drawing for this unit. We have e-mailed and called by phone to the company, but it looks like the company is no longer in business. Thank you to anyone for help on this unit! Thanks ---------------OMguy