Hey all!
good and bad news, i did remove those resistors and i got wave forms like in attached pictures one of the channels seems to work the other is not, faulty chip? or am i still missing something.
though i noticed those spikes they seem to come from my PSU (Computer PSU) when i add 220uF on the 12v supply rail PSU changes sound and that channel stops working, I'm starting to suspect bad PSU.
Hi again. I didn't really get much from that post, so hard to guess
You are powering whole thing from PSU? If yes, the problem may be that this is too tiny load, so I would try to add something like >2W 100ohm power resistor to the 12V rails. You could measure the PSU output directly with your scope, to see what's happening there. That supply could be completely OK... And since you are drawing only like few mA, you can try changing R10 to about 47 - 100 ohm.
The second channel not working is weird. It could be caused by so many different things (short on board, mistake in measurement method, damaged output /f.e. if it was shorted before/, cold joint, wrong connection of probes, schematic inconsistent with board, wrong output resistor value etc.), but not by the mistake in the schematic.
They are internally connected and if channel A works, channel B should work too. Even if you have bad PSU, if you get correct waveform from one channel, you should get it from the second one too. What's more, it's highly improbable that you did get chip that was faulty from the supplier. That is something that almost never happens, especially with not ESD sensitive chip like that.
So I would look for mechanical stuff (like copper "dust" between leads, cold joint), checked the connection and value of R8&R9 (you didn't wrote which channel is not working) and probed directly on the SG3525's pin. And you could also try to power it from another supply (9V battery could be fine for short time, check the input current). PSUs are great powerful sources, but they can have problem with earth loops, especially if you are using scope that is earthed by mains.