Hi all, I have this Harmon Kardon citation 19 on the bench with a strange issue. Reported issue is one of the channels intermittently cuts out after a while.
In order for me to replicate the issue I had to leave the amplifier on for 3 days and use it for a few hours after that, implying some sort of thermal issue?
One of the channels every once in a while throws static and then cuts out. One of the channel indicator lights also flickers whenever the washing machine kicks on.
What should I be testing to diagnose the issue further? Since its so intermittent this issue is very hard to get a read on.
I am thinking recapping the main filter caps should do the trick, do you guys agree?
any advice GREATLY appreciated.
schematic: https://www.manualslib.com/manual/702233/Harman-Kardon-The-Citation-Nineteen.html?page=8#manual
In order for me to replicate the issue I had to leave the amplifier on for 3 days and use it for a few hours after that, implying some sort of thermal issue?
One of the channels every once in a while throws static and then cuts out. One of the channel indicator lights also flickers whenever the washing machine kicks on.
What should I be testing to diagnose the issue further? Since its so intermittent this issue is very hard to get a read on.
I am thinking recapping the main filter caps should do the trick, do you guys agree?
any advice GREATLY appreciated.
schematic: https://www.manualslib.com/manual/702233/Harman-Kardon-The-Citation-Nineteen.html?page=8#manual
Thermal faults are not too difficult to narrow down with the careful use of a heat gun with a small nozzle and freeze spray. If you want to cool a single component such as a transistor, slip a length of heathshrink over it and direct the freeze spray down the tube. Cracks in pcb tracks can respond to hot and cold, and also some gentle pressure from a finger or a nylon spudger. Cover any potentially lethal voltages to remove the risk of accidental contact because you will be doing this testing with a live amplifier. I use multiple layers of kapton or normal insulation tape.
