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Dual CS5000 won't do 33rpm

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xstantonx

New Member
I've done a forums search for a similar problem but couldnt' find a match to my problem so here goes.... I have an otherwise mint and well-cared for Dual CS5000 (with a Sumiko Blue Point) that has a problem locking in at 33rpm.

I've tried swapping belts, cleaning, etc.

I can only imagine that this is the result of the chip or pcb for the speed controller being bad. If you're familiar with the CS5000, it won't drop the arm until the correct speed has been locked in. Sometimes I can get it to lock in by switching to 45rpm and back but this isn't really a good fix and sometimes takes minutes worth of trying.

Is there anyone that can fix this model out there or is familiar with this problem? Is it possible to order a new speed controller board board?

Mark
 
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Thank you for that very generous offer! I hope I don't have to take you up on it but something tells me it's likely.

Thanks,

Mark
 
If you can get in to the speed change switch, I'd clean that 1st. Sounds like it's either got an intermittent @ 33 or something else is causing the quartzlock NOT to. Are the board interconnects push on types or soldered on. If push ons clean them again and use brasso on Q-tips for the male pins and De-Oxit on the female 1/2's.

That's all I can think of short of board level stuff, and I'm not conversant with that level.

Larry
 
The 5000 is a fussy animal. Lots of small plastic parts that are prone to breaking. Your are correct in everything you say - won't set down until perfect speed is achieved (who though up THAT!?!)

Bad logic board - parts unit time.
 
I gave up on it for a while... but got back on it recently.

I think I've ruled out the belt. I bought the Thakker from Germany... still nothing. Tried 2 other belts with slightly different sizing too.

Then, just for kicks, I tried out this app I have on my phone called RPM. It said it was turning at between 34 and 35 rpm. I tried to put a slight and even drag on the platter with my finger until the app showed 33rpm and the speed locked in and the needle dropped!

I wonder what could be causing the speed to be consistently too high? And keep it from being able to correct itself.
 
The belt has always been the fix for your problem in every case I've ever heard of. I would say to keep looking there. Is the platter rim clean, the motor pulley? Is the belt the right thickness? All these things will affect speed. Take the belt off and then move the arm over. Does it lock on speed normally then?

Try a belt from South Street Service. http://www.dual-reference.com/Contacts/SCmain.html . They actually fix duals. Thacker only sells parts. If he gets a bad belt You'll be the first to know not him.

As far as the electronics goes, I went looking for replacements a year ago. I found all the transistors were being obsoleted at that time. The main IC had been obsolete for years already, but I did find one on ebay and picked it up.

As far as I can gather the 5000 looks for speed consistency not accuracy. That's why it will lock on and drop the arm with no belt installed.
 
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