Just given to me. Hardly a scratch. However left channel not functioning. Also hear pop out of left speaker when I turn the speakers on. Right channel works perfctly and so does every other function. Is this an output transistor gone bad or something much easier to deal with? All controls quiet and have not decided to de-ox anything until I hear from someone that it would be worth a try. Any advice appreciated.
Pioneer SX-535 Receiver No Left Channel
- Thread starter Meaudio1
- Start date
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As Bob mentioned dirt a common enemy, all controls and switches need cleaned
first. However make sure you keep the DeOxit away from the tuning condenser.
Thank you both for your advice. So far I have cleaned all controls from the outside(de-ox) and all jacks plus eq switch on back. No luck so far and I must take the botton off to get proper access to those switches and controls. However I am curiuous about the 5 fuses plus the 2 protect fuses in that little box on the back. I cleaned the fuse holders and inspeacted fuses. They are old but all look good. Also wanted to make clear that there is no left channel from the B speakers terminals(tried that) and also the headphone jack even if I press the mono switch. I will continue tomorrow and clean everything under bottom cover plate and advise.
Still No Left Channel and popping noise on speaker select persists
I now have thoroughly cleaned all controls and the access was easy after taking the bottom cover off. I absolutely smother the de-emphasis switch on the back and worked it back and forth about 50 times. Still no left channel out of speakers or headphones. I also noticed a slight burned odor out of one of my Ratshack Minimus 7's so I disconnected it and tried it on the other channel and the speaker seems to be ok. I hate to throw this receiver out as it barely has a scratch and as I said, every other function is perfect. Any advice on what I should do past this point appreciated.
I now have thoroughly cleaned all controls and the access was easy after taking the bottom cover off. I absolutely smother the de-emphasis switch on the back and worked it back and forth about 50 times. Still no left channel out of speakers or headphones. I also noticed a slight burned odor out of one of my Ratshack Minimus 7's so I disconnected it and tried it on the other channel and the speaker seems to be ok. I hate to throw this receiver out as it barely has a scratch and as I said, every other function is perfect. Any advice on what I should do past this point appreciated.
It's time to open it, put in a signal from a generator, and trace with a 'scope to see what's up. Or perhaps trace with a voltmeter to verify that the amplifier is working properly dc wise.
I still feel that one of the switches, tape monitor or -20 dB or such isn't making proper contact. But of course the problem could be elsewhere.
Bring it over and I'll fix it.
I still feel that one of the switches, tape monitor or -20 dB or such isn't making proper contact. But of course the problem could be elsewhere.
Bring it over and I'll fix it.
I just bought the same unit with the same issue with no sound in the right channel. I was ok using the mono until I realized I was missing a channel of the stereo mix. I corrected this by using an RCA plug mono adapter which converted the stereo from the turntable into a mono mix to the left channel than I could hear both right and left mixes together. I’m not electrically inclined so this wasmy band-aid solution but it worked for me. I gotthe RCA mono plug at Radio Shack years ago. I’m ok not having stereo, mono is fine.
PWells1122
New Member
I know this is a very old thread, but maybe you can tell me what did you find as the problem with this Pioneer SX-535 output issue. I just got one with the same issue, no right channel with speakers or Headphones.
I bought a set of Klipsch KG-4 speakers and this unit was sitting there and he gave it to me as non-working.
Thanks for any reply you can send to me.
Dom123
Well-Known Member
Presuming you have checked all fuses and checked the output drivers, I would definitely look at the small transitors on the amplifier board, starting with swapping out the diff pair Q1 to Q4 for hFe matched KSA992 especially if they are 2sa726's. Very easy job, just take a few minutes.
Also activate or push vigorously several times the push buttons, especially tape monitor & mono to see if the sound comes back.
Also activate or push vigorously several times the push buttons, especially tape monitor & mono to see if the sound comes back.
The amp board has 2sc1318's and 2sa720's that are on the known to fail list. I'd start with replacing these.
https://audiokarma.org/forums/threa...ilure-prone-whatever-and-replacements.731653/
The differential pair may be 2sa763, not on the list but anything could be the problem.
https://audiokarma.org/forums/threa...ilure-prone-whatever-and-replacements.731653/
The differential pair may be 2sa763, not on the list but anything could be the problem.
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PWells1122
New Member
I cleaned all of the controls with DeOxit and have worked all of the buttons and knobs a lot. Still the same. I am not set up to do much more and don't have the tools for more. Also, I connected other devices to ensure it was a system issue and not just one of the control switches or buttons. Guess I will find someone with expertise in Vintage Stuff so see if it is repairable at a reasonable price.
Thank you for the reply.
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PWells1122
New Member
Thank you for this. I have printed it to see what I can make of it.
That post was focused on the amp board. Having a channel out could be anything from the input to the speaker jacks.
Maybe let folks know your general location and it's possible someone will reach out to take a look at it.
dly66
Addicted Member
Have to watch it with this vintage. Both the SX-535 and 636 I have dealt with had the 2SA726 in the differential pair spots. Some production runs of these will have 2SA726 in all the spots schematic has the 2SA763. The 2SA763 has a good reputation, 2SA726 on the top 10 or so most problem transistor lists.
Note with DeOxit need to get it on the inside of the pots and switches where the contacts are. Some disassembly may be required to get adequate access to gaps or holes in outer shell to get cleaner inside the pots in particular. Can make a difference. Have a project HK 800+ cleaning controls got a totally dead FM tuner tuning and sounding good using headphone amp on Tape Rec jacks since it did not fix the amp side distorted sound problems. A good cleaning can make it where there are less problems to chase down.
Note with DeOxit need to get it on the inside of the pots and switches where the contacts are. Some disassembly may be required to get adequate access to gaps or holes in outer shell to get cleaner inside the pots in particular. Can make a difference. Have a project HK 800+ cleaning controls got a totally dead FM tuner tuning and sounding good using headphone amp on Tape Rec jacks since it did not fix the amp side distorted sound problems. A good cleaning can make it where there are less problems to chase down.