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New guy, Turntable problems. Pioneer PL-4

J

Justin922

New Member
Hi all,

I am brand new to this site and I wanted to know if someone might help me with an issue. I have a PL-4 that has the common (apparently) speed issue. I have disassembled the table and cleaned the pots directly and I am still having the same issue. It speeds up / slows down but never gets close to approaching 33 or 45 rpm. I am not new to electronic repair but I am a little rusty.

Any help would be appreciated.

Thanks!
 
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Sorry about your problem. I did a google search to see if there was any info and darned if it didn't take me right back to Audiokarma! There are a few discussions about the speed problems in the PL-4 and methods of fixing it. Some mention disassembling the TT and cleaning with Deoxit, which I think you already did, but check to be sure you did as suggested.

There was also mention of the caps needing replacement. I had a Dual with the cap problem and it would run in reverse! Possibly the caps could be your problem.

Do a search for PL-4 and see what you find.
 
I have definitely done my due diligence with de-oxit, I even r&red the potentiometer and tested it (10k ohm, thru the whole range) and it still won't slow down. I've checked about 30 threads with this problem and most of the time de-oxit fixes it.Looking for some info on what's next or at least a circuit diagram maybe?

Thanks
 
Hello,

I have a PL4, you'll need to clean the 33 / 45 switch too. Spray it with deoxit and operate it a load of times.

I'd be really surprised if any of the electronics was cactus, these are very very reliable.
 
Pioneer PL master Beej might chime in and have a suggestion for you, or you can PM him.
 
I think it may be a cap issue. When moving the tonearm to start the motor it will either not move or, turn in reverse for a few seconds.
 
Justin922 said:
I think it may be a cap issue. When moving the tonearm to start the motor it will either not move or, turn in reverse for a few seconds.
Click to expand...

Hi, I know this is an old thread, but hopefully someone can offer suggestions.

The issue above is the exact same issue I am having with a PL-4 I rescued from a flea market. Additionally on my unit, when the motor is not moving with power applied, I use my finger and spin it forward, then the motor will come to life, but in reverse and spin backwards for a couple of rotations and then stop.

I have applied Deoxit via a little hole I drilled into the 33/45 speed switch and pressed it many times. Occasionally, when pressing down or releasing up, I notice the motor attempt to move forward spin for a fraction of a second and stop. Looks like the forward spin voltage kicks in for a split second and disappears.

Am open to any suggestions to bring this PL-4 back to life.

Thanks!
 
Responded to your PM. The issue is in the speed/power circuit. In my experience, regrettably, the only way I've been able to address it is by replacing the entire circuit from power cord up to and including the the speed control board, switch and pot. The PL-4 and PL-5 have the same speed/power circuit. They occasionally pop up on ebay and there is a listing for one there now but it is incorrectly IDed as a PL-5. The pic shows a PL-7 circuit - quite different and will not work in the PL-4 or PL-5.

As I indicated in my PM response, let me do some digging.
 
beej said:
Responded to your PM. The issue is in the speed/power circuit. In my experience, regrettably, the only way I've been able to address it is by replacing the entire circuit from power cord up to and including the the speed control board, switch and pot. The PL-4 and PL-5 have the same speed/power circuit. They occasionally pop up on ebay and there is a listing for one there now but it is incorrectly IDed as a PL-5. The pic shows a PL-7 circuit - quite different and will not work in the PL-4 or PL-5.

As I indicated in my PM response, let me do some digging.
Click to expand...

Thanks for taking the time to go over my turntable problem. I'll wait to hear from you on additional details.
 
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