[ktziavos]

Hello to all! 
I recently built the cp554 compressor. Everything working perfectly until yesterday!  suddenly no sound when it is on. The light is ok. The measurements from the V+- and the the bias are ok. Please where to start searching?? Any thoughts? 

[JPK]

Send a constant sine signal to the input and check if you can measure it with your AC voltmeter on TP1 and TP2, against 0V.
It must vary in level with the input signal and the compressor makeup gain.