Hhuuuuummmmmm

[grtwhthuntr]

I'm sorry but I have read all the posts for this subject, but they all seem to be for newer AS. 71 excella 500, Sony aftermarket radio/cassette deck early 90 model.

I have a seperate toggle switch to turn power on/off to radio. W/ switch on and radio off, I have a terrible hum coming from all speakers. Same when I turn radio on, except music is competing. As volume goes up, the hum stays the same.

Converter is original Univolt (to my knowledge and by the looks of it).

Power switch also gives power to memory lead to radio. Thanks

Chris

[Lumatic]

But I don't see a way you could get any juice to the speakers with the radio switched off unless there is an internal problem in the radio, you have reversed polarity with the power supply, or a bad ground.

[Phoenix]

Usually, a 60-cycle hum is caused by a ground problem. However, if you haven't done anything with the wiring, it's possible that a filter capacitor has failed in the converter. Unfortunately, unless you have some electronics troubleshooting experience, you may have to have a tech take a look at it; and that could be costly, even though it's not difficult to fix.

If you have been messing with the stereo or converter wiring, it's possible that you either left something disconnected (open ground) or you have two leads reversed. Sorry, I can't be more helpful; but a stereo shop or a friend with some electronics background can probably figure out what's wrong.