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Restoring a Pioneer PL-630 Turntable

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The problem with these tables is that the tonearm belt dries out and stretches, causing the table to malfunction in strange ways. The tables are then taken out of service, and wind up in storage for many years. In that process, the pots and switches get dirty/corroded. You need to actuate the "Auto", "Speed", and "Quartz Lock" switches, about 300 times, followed by operating the "Pitch" control across its full range, about the same number of times. You will likely see the problems clear up for the most part. Then you need to get some DeOxit in there and work each of the listed controls about 50 more times each. You should be good to go from there.

Preventative maintenance on these vintage audio pieces is to work all user controls about 50 times, once per month, to keep them in good connection order.

Enjoy,
Rich P
 
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What a marvelous exposition of info :thmbsp:
I can only imagine how many times this "reference" will be used in the future :yes:

Although I will definitely bookmark this one, I implore the Mods/Admins to make this a sticky.

Redi
 
:ntwrthy: :ntwrthy: :ntwrthy:

What a fantastic "how to" thread! :thmbsp:

Although I don't yet have a PL-630, I hope to find one some day, and it does share many circuit similarities to my PL-C590, so I'm printing this thread out and adding it to my notebook, alongside the service manual for the PL-C590. My 590 is a "time machine piece" in its condition, having spent most of its life unused under a protective cloth cover, but still the caps are old and it will be recapped, etc... I'll be studying BOTH the SM AND your instructions before I ever do that recap! THANKS! :thmbsp:
 
pustelniakr said:
The problem with these tables is that the tonearm belt dries out and stretches, causing the table to malfunction is strange ways. The tables are then taken out of service, and wind up in storage for many years. In that process, the pots and switches get dirty/corroded. You need to actuate the "Auto", "Speed", and "Quartz Lock" switches, about 300 times, followed by operating the "Pitch" control across its full range, about the same number of times. You will likely see the problems clear up for the most part. Then you need to get some DeOxit in there and work each of the listed controls about 50 more times each. You should be good to go from there.

Preventative maintenance on these vintage audio pieces is to work all user controls about 50 times, once per month, to keep them in good connection order.

Enjoy,
Rich P
Click to expand...

Rich, thanks for the advise, I'll give it a try to "Deoxit" the switches and control pots first before going into further troubleshooting, but to actuate them for about 300 times sounds a bit far out to me :yikes:

I'm sure they would wear out rather quickly! :yes:
 
Vintageaudio123 said:
Rich, thanks for the advise, I'll give it a try to "Deoxit" the switches and control pots first before going into further troubleshooting, but to actuate them for about 300 times sounds a bit far out to me :yikes:

I'm sure they would wear out rather quickly! :yes:
Click to expand...
You may of course do as you wish, However, DeOxit will not touch the corrosion of the switches, unless you first cut through the corrosion that is there. The contacts are silver, and DeOxit won't do the job alone. Of course you could do as I do, and disassemble the switches and manually clean the contracts with a non-abrasive eraser. I offered you the fix for the non-tech, and with minimum effort.

Oh well. I have only successfully restored dozens of these tables. Just remember my counsel.

Enjoy,
Rich P
 
pustelniakr said:
You may of course do as you wish, However, DeOxit will not touch the corrosion of the switches, unless you first cut through the corrosion that is there. The contacts are silver, and DeOxit won't do the job alone. Of course you could do as I do, and disassemble the switches and manually clean the contracts with a non-abrasive eraser. I offered you the fix for the non-tech, and with minimum effort.

Oh well. I have only successfully restored dozens of these tables. Just remember my counsel.

Enjoy,
Rich P
Click to expand...

Rich, please don't misunderstand my earlier post, I certainly appreciate your input, specially given your experience with these turntables.

But really being a very pro-technical person for many years now (the language in my first post here might have given a hint of that) I know a bit about how 300+ (dry) consecutive operations as you suggested might severely cut into the remaining life expectancy of components like a potentiometer which is basically a very thin deposited carbon track. Unless of course these pots are of the wirewound type, which would of course totally change the picture as they are much more resistant to wear.

On the matter of Deoxit, not sure why you say that it won't do much good by itself to remove the oxide (or contaminant) inside the pots and switches. I would agree that just applying it without giving the part a reasonable workout will not make much difference, but the idea is first letting it soak for some time, and then perform some operations in order to work it in. That way it will also have a chance to loosen up the oxide, and also provide a certain degree of protection to the part itself by lubricating the mechanical contact points, and reduce any added wear that the corrosion deposit may produce. What I would not be too comfortable with, and that was really the object of my first post, is that 300+ operations would have been required to see any improvements, specially if using Deoxit.

But then again, given your great experience on this particular subject, I might be wrong. If this is the case here, I'd be happy to be proven wrong, and learn something new from it.

Thanks.
 
So I put a bit of Deoxit into the speed pot and both the speed selector and quartz lock on/off switches, gave them each a little workout and speed now seems stable and locked in, both 33 and 45.

I was wondering if anyone ever encountered that the arm counterbalance and weight dial seem to be frozen together and turning as one, instead of being able to turn independently. Any ideas on how to free them up?
 
PL-630 to slow

Hello,

got a PL-630 presented from the attic of my uncle. After some cleaning and restoration the table looks great but there is still an error:
The Pioneer cannot hold its speed!
Even with Auto-speed=on it does not reach it, it is just a little bit to slow, maybe 3-5%. Also this decelerated speed is not absolutely constant. Watching the indicator in the pitch-window it looks like the table "knows" that it is to slow, tries to speed up but falls back again. There is also a very silent "klick", perhaps once a second, which seems to correlate to the fluctuation of the indicator.

So what should I do to fix this problem? Looking forward to any kind of help!

Greetings, Norbert
 
Nobbixxx said:
Hello,

got a PL-630 presented from the attic of my uncle. After some cleaning and restoration the table looks great but there is still an error:
The Pioneer cannot hold its speed!
Even with Auto-speed=on it does not reach it, it is just a little bit to slow, maybe 3-5%. Also this decelerated speed is not absolutely constant. Watching the indicator in the pitch-window it looks like the table "knows" that it is to slow, tries to speed up but falls back again. There is also a very silent "klick", perhaps once a second, which seems to correlate to the fluctuation of the indicator.

So what should I do to fix this problem? Looking forward to any kind of help!

Greetings, Norbert
Click to expand...

Dirty speed selector switch, quartz lock switch, and speed pot. DeOxit is your friend. The restoration thread should give you the instructions you need...

In a pinch, you could try operating the listed switches 100-300 times each. Do not worry about wearing them out. There is very little danger of doing that. As a matter of fact, they got the way they are by NOT actuating them for long period(s). If the problem improves, you will know that you are on the right track.

Enjoy,
Rich P
 
Hi Rich,

thanks a lot for the quick answer!
During the next days I will go and buy some DeOxit, mine's out.
BTW: What is the "speed pot"? The knob for adjusting the pitch when Auto-lock=off? (Sorry for that, but this in no usual shortform in Germany.....)

Greetings, Norbert
 
Nobbixxx said:
Hello,

got a PL-630 presented from the attic of my uncle. After some cleaning and restoration the table looks great but there is still an error:
The Pioneer cannot hold its speed!
Even with Auto-speed=on it does not reach it, it is just a little bit to slow, maybe 3-5%. Also this decelerated speed is not absolutely constant. Watching the indicator in the pitch-window it looks like the table "knows" that it is to slow, tries to speed up but falls back again. There is also a very silent "klick", perhaps once a second, which seems to correlate to the fluctuation of the indicator.

So what should I do to fix this problem? Looking forward to any kind of help!

Greetings, Norbert
Click to expand...

Hi Norbert,

Clean the speed control potentiometer and the associated switches with Deoxit and operate them a couple of times. All your problems will go away. It worked for me like magic.

Good luck with the restoration, it's definitively a great turntable worth the extra effort.
 
Nobbixxx said:
Hi Rich,

thanks a lot for the quick answer!
During the next days I will go and buy some DeOxit, mine's out.
BTW: What is the "speed pot"? The knob for adjusting the pitch when Auto-lock=off? (Sorry for that, but this in no usual shortform in Germany.....)

Greetings, Norbert
Click to expand...

Speed pot = Pitch Control
Speed switches = Quartz Lock on/off, and the 33/45 speed selector.
 
Vintageaudio123 said:
So I put a bit of Deoxit into the speed pot and both the speed selector and quartz lock on/off switches, gave them each a little workout and speed now seems stable and locked in, both 33 and 45.

I was wondering if anyone ever encountered that the arm counterbalance and weight dial seem to be frozen together and turning as one, instead of being able to turn independently. Any ideas on how to free them up?
Click to expand...


Hi,

thanks for your help!
Bought some Deoxit today and will give it a try in the next hours.

BTW: My counterbalance and weight dial seemed to be frozen together also! But gave them some pressure and they were seperating. So after some cleaning they operated in the usual way as known from other turntables.

Greetings, Norbert
 
Rich and AK'ers,

I recently picked up a 630 that exhibited many of the problems that have been documented here. Thanks to all who have posted their experiences here so that we can benefit from it!

I have a question for those who have long term (and multiple sample) experience with these tables:

I've restored the auto functions and everything's working fine and tweaked out per Rich's instructions. (I skipped the recap, which might be important with regard to what follows..) It took a while and boy was Rich dead on when he said to leave the record size/repeat controls alone, they ARE touchy.

BUT..... there is a very faint motor noise (it modulates up and down with the mechanical load) in the LEFT output only that accompanys all auto functions (including tonearm up and down) that I just cannot null out.

Did they do this when they were new?

It's innocuous enough and once the tonearm's where it's supposed to be (the unit's very quiet otherwise, electronically and mechanically speaking...) it's a total non-issue. I'm just hoping to get a baseline for "normal"......

Thanks in advance to all for their input!

Rick
 
Ricktptman said:
Rich and AK'ers,

I recently picked up a 630 that exhibited many of the problems that have been documented here. Thanks to all who have posted their experiences here so that we can benefit from it!

I have a question for those who have long term (and multiple sample) experience with these tables:

I've restored the auto functions and everything's working fine and tweaked out per Rich's instructions. (I skipped the recap, which might be important with regard to what follows..) It took a while and boy was Rich dead on when he said to leave the record size/repeat controls alone, they ARE touchy.

BUT..... there is a very faint motor noise (it modulates up and down with the mechanical load) in the LEFT output only that accompanys all auto functions (including tonearm up and down) that I just cannot null out.

Did they do this when they were new?

It's innocuous enough and once the tonearm's where it's supposed to be (the unit's very quiet otherwise, electronically and mechanically speaking...) it's a total non-issue. I'm just hoping to get a baseline for "normal"......

Thanks in advance to all for their input!

Rick
Click to expand...
Sounds like you need to clean the contacts of the internal audio cable connections (where the cables plug in). A poor ground connection will make such sensitivity manifest.

Enjoy,
Rich P
 
pustelniakr said:
  1. Do nothing to the disk size and repeat buttons. DeOxit is no good for snap dome switches.
Click to expand...


  1. i have the PL-610 and the switch layout is somewhat different. in my case, i believe the "arm up/down" is the snap dome switch mentioned above. when the button is pressed, a plastic piece on the bottom of the button contacts a black spring/loaded switch soldered to the PC board. there are two metal shafts encased in plastic that look sort of like nails and serve to guide the button's path. i don't know if there are springs in there or what, but i'm having trouble with the button popping back up. not sure why, and i don't know what to lube it with. any suggestions? thanks!
 
i took everything apart again and played with it, and now it works fine. i think part of it was an alignment issue from putting the table back together after the first time it was apart. the switch did have some issues before, but it had stopped working altogether. the table's finally back to 100% again and i can send my Micro Seiki MB-18 back to the bench. the PL-610 kicks it's a$$.
 
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