Crafter DSP1 guitar amplifier

[Synctime]

Someone in this forum reported 11 years ago that his Crafter DSP1 guitar amplifier is making a constant hum but he was unable to fix it.

https://ssguitar.com/index.php?topic=3769.0

I have recently bought the same amplifier and it's also making the same constant hum even with no input, exactly as he described. I am unable to contact the author, and ask him if he made any progress or if he can sen me a copy of the schematics.

I am an electronics engineer so I am hoping to continue wjhere he left off, or has anyone in the forum found what cause the hum in this amplifier. Any help is greatly appreciated.

[g1]

Schematic is in the first post of that thread you linked.
There are a lot of things that can create hum. His problem is not necessarily the same as yours so you should go through that whole thread and see if the checks suggested get you anywhere.