Pioneer SX-525 channel issue - newbie needs help

[66BigBlue]

I’ve got a pioneer sx-525. The left channel has almost no sound coming out of it when it is in stereo but comes on in mono. I have cleaned all pots with deoxit and have checked all fuses. Are you able to guess what the issue might be? Based upon what I have read it seems like it could be bad output transistors?

Now the challenging part. I am a newbie with only a beginning knowledge of electronics but I want to learn. I’ve built a dim bulb tester and have a multimeter. I have also replaced caps and some basic testing. How do I start to diagnose the problem? How do I test the output transistors without removing them? Any help would be much appreciated.

 

[llwhtt]

Since both channels work when in MONO the power amplifiers are fine. The problem will be in the preamp section, dirty switches is the usual problem. Try exercising all of the switches, mode, tape monitors, etc.

Craig

 

[66BigBlue]

Craig you are a lifesaver. I thought I had cleaned and worked everything. I took your advice, worked everything for several minutes more and sure enough both channels are now working well. Thank you.