I got one of the HK525 factory refurbished models from One-Call and I've had it running for about 4 days now. I have it in a cabinet with about 6 inches above it and a pretty good hole behind it.
When I walk in the room I can smell something like a plastic, burning smell. The unit also runs very hot. The unit only has to be on to produce the smell, not doing much.
The sales rep says that it was burning some sort of glue or plastic because it was new and should burn off but it seemed weird to me.
Other than the smell I have had no other problems. Great sound. Anyone have any suggestions?
My guess is you are not providing enough venting. This receiver can handle all sorts of load, but you need to let it breathe or it will get very hot. I have about 9" on top, 2" on either side and a good size cut-out in the back of the cabinet, but it was still getting quite hot. Solution: Added an exhaust fan to the back of the cabinet and I can leave it running all day with no problem.