Http://www.head-fi.org/forum/thread/233646/repairing-denon-avr-900-receiver Above find a forum that discusses your exact make.
http://www.service-manual.net/ashop/catalogue.php?cat=142 You need to start at the Power supply and check you voltages are as marked. Further then, check your Output Device(s) These are usually what fail. They are a reasonably available device, and is quite easy to replace. Really you must get a service manual above, a pay for one is all i could find though. However these are worth their weight in gold and soon make it able to isolate and repair, also has all part numbers to order new parts.
Answers & Comments
Http://www.head-fi.org/forum/thread/233646/repairing-denon-avr-900-receiver
Above find a forum that discusses your exact make.
http://www.service-manual.net/ashop/catalogue.php?cat=142
You need to start at the Power supply and check you voltages are as marked. Further then, check your Output Device(s) These are usually what fail. They are a reasonably available device, and is quite easy to replace. Really you must get a service manual above, a pay for one is all i could find though. However these are worth their weight in gold and soon make it able to isolate and repair, also has all part numbers to order new parts.