Mackie SRM450 v1 - No audio output

[beavernuggetz]

For curiosity's sake, I'd attempt to test the comparator and opamp you replaced on a breadboard or something. I won't be entirely surprised if they turn out to be working fine, meaning the actual problem was bad solder joints. The speaker seems to have been through some things, so finding some of those wouldn't surprise me in the least.

You are probably correct on that one; my friend only brought me the amp originally until Sunday when he brought the actual speaker for testing.
I do not remember hearing any faint music sound before replacing those SMD components, but it is possible we did not pay close attention either.
Now thinking back, the issue could have been the potentiometer the whole time.
Any idea where to find a replacement? I'm having trouble locating one and just opened, cleaned, and bent the contact pins a bit which seems to have restored the resistance when turning the knob although it needs to be tested after soldering it back in place.

 

[AnalogSteph]

Now thinking back, the issue could have been the potentiometer the whole time.
Any idea where to find a replacement? I'm having trouble locating one and just opened, cleaned, and bent the contact pins a bit which seems to have restored the resistance when turning the knob although it needs to be tested after soldering it back in place.

Good save.

Got some pictures of the culprit? If you are lucky it's something off-the-shelf.

 

[beavernuggetz]

Happy to report that the Mackie is fixed.
Did some digging and ordered a pot replacement from China (Aliexpress) which works fine.
RK12 Type A10K Vertical Volume Potentiometer A103 D Shaft 23MM 6Pin
Really grateful for the help extended by @LTig as well as @AnalogSteph
Hopefully this thread helps someone else in the future with similar issues.