I have a 3 year old harmon kardon receiver (has served me well so far) that recently developed a "hum" that changes only slightly with volume changes (unless turned all the way up) is intermittent (but there most of the time) and changes between components. I did not notice it starting with any one component being added. I've tried individually unplugging all components without isolation of source and even unplugging the cable tv line coming from the wall (often cited as the most common culprit). I fear that it may be my receiver. Is there anything else for me to try? If it is my receiver can anything be done about it? Thanks
J. Vigne
Unregistered guest
Posted on
If the hum is present with all components disconnected, the problem is in the receiver. 60 Hz hum is most often caused by a capacitor problem.
j. Vigne, Is there anything i can do about a capacitor problem?
J. Vigne
Unregistered guest
Posted on
Only if you know how to trace the bad component on the board and do the replacement and final adjustments. The bigger problem is whether the bad cap has caused a problem down line in the circuit. If the 60Hz AC noise has filtered through to components that expect to operate only on DC or put undue stress on the other components, there may be more than just a capicitor to replace. While it is impossible to predict when a resistor will blow out, just as with a lamp (which is, in essence, a resistor), a competent technician will look over the entire cirucit for potential problems and alert you to their existence. There should also be a warranty on service after a repair is made by a technician. If you are not completely confident in your capapbility to diagnose and treat the problem, I would take it to a shop should you find the hum is coming from the receiver.
J. Vigne
Unregistered guest
Posted on
The first thing to do is to isloate where the problem exists within the system.