Audio Systems: large bang when receiver is turned on, filter capacitor, sony receiver

Question
Sony receiver pops so loud that it activates internal protection device that has to be reset.  It doesn't happen every time.  Can you help?  Thanks

Answer
Sounds to me like the large filter capacitor in the power supply is about to fail. I do not recommend fixing units like these if  they are too old and can be replaced cheaply unless you are friendly with an electronics technician that won't charge you a fortune just to evaluate the unit. Remember that any repair will not be covered under warrantee unless you bring it to an authorized factory service. Usually the longer it takes to repair the unit means the more difficult it is to get parts for it.