I really think
@TOPPING-Service and the reseller are the ones to handle this.
And, without schematic it seems low probability to have a positive impact here.
My recommendation: put it back together and see if you can get Topping to do their job.
My agenda here is to get Topping to change business practices for the better. Even if you could confidently fix the amp, I am still interested in hearing Topping tell you they will provide pre-paid shipping label for an easy warranty process, or a complete refund.
And to stop these practices which are:
Unsafe.
Unfair since they put the burden on the customer to prove defect.
Unfair since they will do this dozens of emails, which ends up exhausting the customer.
Unsound since many of us have been asked to mark the return unit with fraudulent value, seemingly to avoid customs.
I'm not doubting your ability to fix (OK, maybe I am just a bit!!!
), rather I am trying to force the Topping and the resellers to agree to address this.
Recognize that Shenzhenaudio would have sent the email with the link to disassemble the PA5 to my 90 year old mother, who lives alone and is a danger to herself when armed with instructions like this! Literally, she gonna go get some of my dad's old tools (vise grips, etc.), and my
only hope is that she is unsuccessful in cracking open the case!!! Any outcome is better than my mom and the internal guts of electronics coming in contact.