So I took it apart in hopes to find an obvious issue like a loose nut shorting conductors but nothing, spent an hour with a magnifying glass looking for issues w/no success. Found a couple of loose solder flakes which looked promising but that wasn't it. What I did find is that the aluminum case isn't grounded. The equipment ground conductor lands on the PCB ground plane and then nothing. Only one brass standoff has continuity to ground but it happens over a 1mm wide printed conductor which will evaporate way before your circuit breaker clears a ground fault, that is if there is a good contact between that standoff and the anodized case in the first place. Standoffs are 4mm tall and the power header pins are protruding 2mm on the bottom of the PCB, so there is only 2mm gap between mains voltage and the case. With so much noise here around similar problems with Schiit products it is surprising this Topping issue went unnoticed.
The response from Topping indicated, verbatim, "one or two DAC chip of your DX7s already loosed". Sounds like if your DX7s DAC chips haven't loosed yet they may soon.
I could revive the display a couple of times, it would allow me to switch between inputs, adjust volume but no sound and finally show the same error fairly quickly.
