Excursion HXA 5K

Received this amp, completely burned down. Removed all parts, check oscilation in the tl494 .Ok.


After i installed new drivers, no more oscilation.
Pin 3 of the TL has 5V. Ground this pin, oscilation starts.
This pin is connected to a few transistors, which are going likely, to a second LM393.


Maybe somebody has a diagram?