personally i like qxd1 design, but failure rate + weird controls (one vol control on hardware buttons, and two alsa software controls – all independent from each other(!)) convinced me to sell my unit. never knew warranty is only 6 months and i assumed it's 12 instead. was Your unit plugged directly into surge ups? i doubt it has a quality usb power support. knowing it is fragile and might fail on inproper power input i plugged mine unit into one of the top measured PS from the list:
https://lygte-info.dk/info/ChargerIndex UK.html (i think i got apple A1400) and i never induce it to electrostatic discharge (?), so for instance no dust cleaning when it's powered on, and always tried to ground it somehow. Soncoz said they have fixed discharge issue in newer batches and it convinces me to try their products one day again, but at the time being qxd1 was a bit immature it seems…
anyhow if You can locate damaged component and find normal (not „audio qualified”) technician to solder it out and replace with
same part (not cheaper replacement), You can probably fix fairly cheap and retain same performance. there is a chance some soldering point got loosen, or a simple element like capacitor needs an exchange. We have plenty of skillful users here on asr, someone might be able to diagnose it if You open it up and document PCB with camera.
If you don’t have SMD de/soldering tools you can carefully cut the opamp out with precision cutters and then use soldering iron with a thin tip to remove remaining pin material from the pads and solder back a new part. Don’t overheat the soldering pads as if they come off you’ll have a more difficult problem on hand.
