SC-HT900 AM radio signal being heard through Subwoofer


Here is the modification to The SV-HT700/900 if home Theatre system is installed close to AM broadcast transmitter, RF from radio station gets into Subwoofer ( Affected AM frequency range 1000Khz - 1500Khz )
Cause System cable pick up AM signal through subwoofer signal line and rectified as audio signal in one of preamp/amplifier stages in the circuit
SC-HT700 remove cover DVD player find J292 at rear of PCB, remove and add 1K/ohm resistor.
SC-HT900 removed cover DVD player find J270 at rear of PCB remove and add 1k/ohm resistor.
I live 1km from five broadcast radio stations could hear a station on 1260KHz clear with modification done......nothing !!

Cheers Mike

I have the same problem with my SC-HT700, although I just bought it and don't want to do something as drastic as replacing a resistor. Do I have other options? My setup is as follows: cable outlet from wall to tv via coax, tv to dvd player via component video cables. NOTE: When I remove the coax connection from the wall, the AM signal stops coming out of the subwoofer. I tried attaching a Radio Shack RFI filter thing that plugs inline with the coax but that didn't help. I'm going to try a ferrite choke and see if that helps. Am I barking up the wrong tree?

BTW, is this a problem specific to the Panasonic? Or would I have this problem with other similar home theater systems?

New member
Username: Dee_seal

Denton, TX

Post Number: 3
Registered: Mar-04
I have that problem and I am about to do this fix, I have located the J270, do I just place a soldering iron on it till it comes loose, and then gently yank it out with a needle nose pliers? Then place some solder on the ends of the resister, heat it up and place each end in there? I am figuring thats how it is done, anyone who has done this advise is requested?
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