Well, I'll just repost what I wrote on YT. For exact model... in 5 days
Actually I've had similar problem with my Onkyo (newer model). Relay off after turning it on, or turning off during increasing volume. Tried to search for schematics - 0 points. Than, before trying to open it, I've roamed thru net and YT. Found some folks talking about heating from outside prior and during turning on, left side from top of receiver with hair dryer for 3-5 min on max temp! Well... what's the worse it can happen right? Guess what? It worked. Dunno how, but that receiver is happily buzin' last 4 yrs without a single issue