Thonet & Vander - Kürbis, TDA7265

Hi guys.
A friend gave me a
Thonet & Vander - Kürbis monitor for repair that turned on but would not sound. After checking the main amp board, I found an exploted ceramic cap between two 4700uf 25v filter caps, a burned 470R resistor, an a black mess that couldn't possibly come from just this exploted cap.
It has a TDA7265 inside. I managed to rebuild the pcb (kind of.... ). The TDA7265 does produce some sound but it's way to low for 25w.
Voltage at the filter caps is +/- 20 VDC.
Maybe I missed something.
Or the Tda7265 is defective.
Any ideas?
 
TDA7265 is sensitive. I know it as I have replaced a few with the same symptoms so an internal short in the IC often with cracked casing. I would have liked to know if the IC meanwhile had been changed but could not find anything.