It could be worth purchasing if the price is right. Cheap I mean. The A250 is known to be a good performer and have a long lifespan. From a design standpoint the Acurus is a simple design in the way the circuits are made. It's not an overly complicated amplifier. I have read that the capacitors are fairly expensive if one goes bad. If you have a good AV repair shop in your area a bench test of the amp to diagnose the problem will probably cost $30-$50 dollars. It's up to you if you want to take a chance. You have to wonder why the current owner hasn't had the amp checked out already? The channel overheating could be a problem with his speaker and nothing to do with the amplifier. If you're lucky that will be the case. Good luck.