Pioneer A-50DA-K No Audio Repair

A walkthrough of the troubleshooting and repair process for a Pioneer A-50DA amplifier that I bought from Gumtree.
The amplifier presented like new, but reportedly had no audio. It also wasn't flashing any error codes so none of the internal protection circuitry was being tripped.

[@civic952]

I have this amplifier, how do you assess the quality of workmanship and sound, because I miss a little smaller bass and the rest I'm impressed with how it sounds.

[@antonralph6947]

Is it a good amplifier? Would you recommend it?

[@civic952]

​@@antonralph6947I have it and it's really good for the money 💵 it consumes 70w in class D but the sound 🔊 is super detailed, fast, I've had it for 5 years now, and it works about 3 hours a day and everything works.

[@m3g4byte]

My only comparison is a Cambridge Azur 840A and this just sounds better to my ear.