Onkyo TX-SR804 Receiver “No Sound” Repair

This amp suffered from having no audio output to the speakers. The vast majority of Onkyo repair videos focus on DSP chip problems that were common in the later models. This amp is a little older and doesn’t use that particular chip so I had to search elsewhere for the fault. Long story short, test of your headphone socket is working. If they’re getting audio then all the complicated stuff is working, it’s just the output relay that isn’t being switched. In my case there was a loose cable inside which is easy to fix after removing the tuner and one PCB. Hope this helps others!