I have a HK AVR 220. I turn it on but 45 seconds later it will go into standby mode. If I turn it back on, 45 seconds later, back into standby. I repeat this for like 10 minutes or so then it will stay on after that. I can leave it on forever, (it doesn't shut down once its warmed up) but im afraid while im asleep it would catch fire or blow up. When I first start the "warm up" (that's what I call it) process I hear sound just fine, no glitching (besides shutdown) or anything. I can use buttons, switch inputs, everything.
I was wondering if anyone had any suggestion for me to try and fix this. I could replace it but I would rather see if I could repair this myself first.
A little more info. I warmed it up with no speakers or devices connected to it, and it worked. I checked to see if any rogue wires were bridging connections with any outputs/inputs, there were none. I also noticed it gets really hot. So to prevent it from burning out I place a 120mm fan (removed from an old computer) on top of it near the power supply. (not sure whats its call but I know the power cord goes into back near that area) As I bought it off Ebay used ($45 I was expecting quirks) I cannot tell you the history.
The most common answer is; if you cannot troubleshoot the problem, you cannot do the repair yourself. Both take a schematic and the ability to read a schematic to follow a circuit. Both require test equipment you more than likely do not have or have access to plus the ability to know what you are testing and what results the equipment is providing.
Then you need access to HK parts in most cases. HK, like other audio companies, does not sell parts to consumers and repair shops do not sell parts to consumers. Where will you obtain parts?
This is a receiver that is likely to be a more than 15 year old design. Mass market AVR's have an average life span of about 5 years. By then the features and functions of an AVR are outdated and new features and functions make it not worth the money to repair the component. Shops clear out their back catalogs of service manuals about every six or seven years so I doubt you will find a shop willing to take on the repair as they have been telling customers for over a decade to simply scrap the old and buy new.