Audio Systems: Toyota Repair, toyota stereo, toyota avalon

Question
-------------------------The volume will increase and decrease by itself. It isn't a drastic change in volume. It bothers my wife more than me. I bought the car used about 4-6 months ago. I don't really know the history.
Followup To
Question -
Hi Tom I have a question regarding a problem with My Toyota. The car is a 2001 Toyota Avalon. The problem is that the volume will increase and decrease. It doesn't matter if you play the radio or the disc player. Is this a common repair and can I repair from the comfort of my home?
Answer -
John,
Please give me a little more details about how the volume is working. Does the volume go up and down by itself? I have seen a volume problem on a Toyota stereo a few months ago that was caused by corrosion on the control board due to some body spilling soda or beer into the control head. A few other units that I repaired had failing capacitors in the electronic volume circuit that would make the volume go slightly louder all by itself.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net

Answer
John,
I looked over my repair files for Toyota radios and I found two entrys that mentioned volume up and down changes caused by a defective solder connection in the audio control section. An easy test to try is to pull the radio out of the dash as far as you can and then with the radio on, use a plastic handled screw driver and lightly tap on the metal case. If the sound goes up and down you will know that a defective solder connection exist.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net