@audioville I ended up getting a 3rd A90 (after considering other amps) and so far, so good. Depending on where / when you purchased the A 90, you may still have a warranty (I think it is a 1 or 2 year warranty?). I purchased the Topping "ensemble" D90 MQA & A90 from Apos. They were very slow to respond but they eventually replaced both failed units. (They don’t reveal if their online support is in China or stateside, or if stateside has to get approval from the China manufacturer so it’s odd. Their email support comes in flurries at odd times suggesting they're based overseas; it is messy and disorganized.)
I’d also check if you are using an aftermarket (Hart, Periapt, or other) balanced interconnect and/or headphone cable whether or not it "shorted" and caused the problem. This is hard to diagnose and hard to find an engineer on forums who might explain if this could even cause the issue. At some point, you stop wasting time on what happened and just replace the cables & get a new A90 and get back to music. :-) I very well may be wrong, but I am suspicious if a cable could cause a short or damage to the amp.
I hope you are able to get it replaced. When it works, I love the A90 & D90!
I’d also check if you are using an aftermarket (Hart, Periapt, or other) balanced interconnect and/or headphone cable whether or not it "shorted" and caused the problem. This is hard to diagnose and hard to find an engineer on forums who might explain if this could even cause the issue. At some point, you stop wasting time on what happened and just replace the cables & get a new A90 and get back to music. :-) I very well may be wrong, but I am suspicious if a cable could cause a short or damage to the amp.
I hope you are able to get it replaced. When it works, I love the A90 & D90!