sadly the warranty has passed and the device was gifted to me. as for the size of the stock volume knob:

for those who are interested some pictures of the inside of the Topping A90 (not the A90D). I removed the volume knob by putting some tape on it and pulling it with pliers. I cleaned of the thermal paste since it was sitting on the terminals of the NFCA modules

Awesome, I didn't think about removing the volume knob, dumb me. Thanks for the info!

Sadly I already tried that and even checked the fuse. maybe @BowWazoo has an instruction on how to open this device since I saw he had a picture of the NFCA modules?

Hi all, I recently got the ''red blinking light of death'on my a90 and I was wondering if someone managed to repair it. I was also wondering if someone knows how to open the case, is super snug and hard to disassemble the chassis? Cheers!