Soundstream STL1.1200D

[mild2wild]

Need some help with one of these monoblocks. There are many clones going by many names so hopefully there should be a lot of knowledgeable help available. I received two, both need repair. One works but had distorted output, while the other didn't power up at all. We will start with the semi-functional one and maybe I can repair the second one by myself once I have a proper working amp as reference. I am ordering some parts and would like to know what should I order just to be sure to have any possible replacement parts on hand.

I need to know what transistor at Q17 connects to pins 11 and 12 of the TL494?

Is U14 the optocoupler that can be replaced with a 6N137?

What else should I order that may need replacement in this/these amplifier(s)?

 

[Perry Babin]

http://www.bcae1.com/temp/SLA1500.pdf

 

[ray9043]

Hey, can you fix it?? I have the same problem,, i replace the optos with 6n137, but maybe it need to have NOT output. The original parts are scratched, and the diagrama from perry dont has the ic number-name.

 

[MarioRestucci]

I confirm, the scratched IC is 6N137.
to repair this type of amp, an oscilloscope is necessary!
It is necessary to check if there are correct signals on the gates of each output device, before installing the new mosfets.
To do this, it is advisable to remove the rectifiers, using as reference (always) the source pad of the mosfet concerned and injecting a 100hz strong signal at the input of the amplifier (turning the potentiometer of the LPF and GAIN at maximum and excluding any subsonic filter and / or bass boost).