My harmon kardon avr 240 7.1 receiver has been working perfectly until I used it at a high db (around 9). Afterward the front main speakers stopped working. I hooked up 3 other pairs of speakers to make...
Without a schematic, you can take it apart and look around, and check any fuses you find. Sometimes, fuses are used in the form of "fusible links", which are very low ohm resistors in the input circuits to amplifiers, or in the power feeds to them. They're hard to identify without a schematic since they look like a small, metal film resistor, but they're usually about 1 ohm. If you're good at the resistor color coding, you can read and measure any you suspect as being one, and possibly locate it.
Otherwise, sometimes the main transistors in that amplifier circuit can go bad, or some other discrete component. In that case, you have to get a schematic and oscilloscope to figure it out.
Find your output to the front main speakers, and try to identify the part of the circuit that leads to it, to help narrow your search.
If this doesn't work, it will, unfortunately, have to be serviced. Check with a local tv repair shop, or contact Harman Kardon Support:
Hopefully, you will find a bad fuse or link.
Good luck, and hope this helps
Jan 21, 2011 |
Harman Kardon AVR 240 Receiver