Technics SL-1210MK2 - weird speed problem

an update..

Thought I'd share my (non-)progress so far..

I've tried replacing the pitch control, platter, and the pitch control IC (IC301-AN6682). The problem persists.

I'm right now trying to obtain the following spares:

SFMZ172-01E (i personally think this is the problem)
IC201-AN6680
IC101-AN6675

I'll replace those parts in the order mentioned and let you guys know how it went.

m.
 
I've got the same weird speed problem as you mnsh.
Put the pitch at -8% and the platter starts freaking out. From -6% to +8% it will be fine for about 5mins then it thinks it playing a 78RPM record! The only way to reset it back to normal is to switch it off.

Any luck on diagnosing your TT mnsh?

Dan.
 
No worries.

Thats how I diagnosed it aswell, just unsoldered the chip and refitted it into a working SL1210 mk2.
The SL1210 showed the exact same problem as the faulting SL1200 mk5 did.

I think the Technics SL1200 must be setting some sort of record now as the longest running peice of hi-fi equipment that has hardly been changed.
 
Hi!
I have the same kind of problem with one TT Technics Sl 1210 Mk2.
It worked just fine till one day when it begun loosing the speed after a couple of minutes after start or so. Now the platter doesn't move at all. Sometimes when i press start it moves a litlle bit but then it stops.
I think it might be the same problem,but i can't find anywhere other IC201 and IC202 to replece them!
Does anybody knows where i can find them ,or if i can buy them from somewhere??
tnx!
 
I would try cleaning the contacts of the speedbutton and the pitch control with some contact spray. Also check the connections on the motor circuitplate below. Disconnect and reconnect them to be shure.

If that does not work just read this topic again, and start checking the soldering on the parts one by one. If you really must replace the IC201 or any other IC, take a look here for the service manual. It tells you where they are. The IC201 would indeed be your best bet and is located on the motor cicuitplate. Bottom-right here:

An externally hosted image should be here but it was not working when we last tested it.


;)
 
One thing you could check is the voltage at TP5. It should be 20 volts. This is located under the turntable platter, on the motor drive circuit board. Its under the silver coil sheild and right next to the word "PITCH". You'll see a printed 20V with a box around it. If you don't get 20 volts here, probably think about replacing the external transistor that is held down by a little clip and two screws. Its connect to the drive circuit by three wires and it has its own little curcuit board.
 
Parts suppliers

Going back to the unstable rotation post, I'm in the process of figuring out what the issue is and this forum has cleared a lot up for me. My plan now is to get a replacement AN6680 (IC201) but the service manual also states that I should replace SVQU306115 (Crystal X201). How do you guys feel about this? Out of the two people that have followed up it appears IC201 has done the trick. Experienced opinions, anyone?

Also, where are you guys buying your parts from? Are any of you parts dealers?

Oh, and the service manual for the 1200 that was previously posted is seriously lacking. Attached is the complete one.

Thanks,

Allen
 
Hi ,
I picked up a SL1200 a couple of days ago. It also has a speed problem. In my unit the speed fluctuates around the correct point. Not a huge amount but enough to make it useless to playback a disc. The change is rapid .

Allen95060 , can you send me a pdf of the manual ?
ashokm(at)sify(dot)com

I haven't opened up the machine yet but will probably do something today.

Is the SL1300 a good machine ? A friend has one and never uses it. Might manage to exchange it for some other equipment. Worth it ?
Cheers.