Technics SL-5210 runs too fast. Search fro Service manual and help

Hi,

I´m in need for a servive manual for the Technics SL5210. This was one of the first models of Technics with quartz controlled drive.
My model runs much quicker -and the same to high speed on both 33 and 45. Switching quartz-control off there´s no reaction to the pitch.
It also seems that the series pass transistor that regulates the supply voltage gets too hot.

The chipset consists of the AN640G (IC101, Drive), AN660 (IC202, Control), DN860 (IC203, frequency Divider) and the µPC4558C (IC201, FG-amp).
The PCB is named SFDP-520-31(a)

The Technics SP-15, of which I got the service-manual, uses also this Chipset, but differs in details like speed-switching and oscillator-circuit.

Can anybody supply me with the SL-5210/5200- Series service manual?
Or does someone at once know what the Problem could be?

thanks
Calvin
 
Hi,

did some measurements yesterday. Found, that the FG connection points on the PCB just have a DC-potential. Shouldn´t there be a turns-related signal (some pulses per revolution of the platter)? I assume that the control circuit doesn´t get the ´feedback´ from the rpm-sensor so that it puts out too high rpm-steering signal to the motor.
Any suggestions?

jauu
Calvin
 
Hi,

found out, that the FG-Generator indeed didn´t work, even though when measured it showed some 5Ohms resistance. The FG-generator is just printed on circuit board in meandering pattern. Its located on the aluminum ring of the motor circumference, that is covered by a white plastic ring.
Its signal is generated by induction of the rotating magnet fixed to the platter. So its a passive system not requiring any external power source.
As such turning the platter must generate some form of signal. Closer inspection revealed a barely visible crack in at least one of the soldering points on the PCB. Resoldering fixed the prob and the coil now measures around 2Ohms resistance. It now provides the necessary pulsed speed signal again and the TT turns with its nominal speed again.

Still though I´d appreciate if anybody could supply me with a manual, because the manuals that I used (Sl1300ii-17ii, SP15 and SP10ii) are similar but not equal and I liked to do some tweaking with the regulating loop of the control circuit.

jauu
Calvin
 
Hi,

dicovered the link also and already downloaded it. Fortunately the original prob solved quickly and easily (it was a tiny, bearly visible crack of one of the FG-generator coil contacts. So tiny, that some ohms resistance were still measureable).
Thanks for Your help anway. I can now take a closer look at the different signals of the loop to tweak or optimize the motor run.

jauu
Calvin
 
This fix worked for my SL-5200. Thanks a ton!! It was spinning incredibly fast, then shutting down, and starting again. I checked the part Calvin described and noticed the cracks in the solder. After the problem was corrected - perfect timing. Thanks for the tip and the accurate descriptions.
 
Hello Calvin & all!
I have a Technics 5210 turntable with the same speed issue you mention in your post. Could you please tell me where you found the problematic solder? I just opened it and can see the guts in the picture but I'm not sure what you mean when you mention "FG". Do I have to dismantle the metallic plate under the motor? Please check the attached picture.


Imgur: The magic of the Internet



Thanks a lot for your time!
 
Hello all!
I figured it out myself. :)


Please open the below image for reference:

Imgur: The magic of the Internet

1 Open the back of the turntable. Unplug the connector marked with the red arrow.
2 Flip the tt over. Remove the 3 screws in the aluminium ring that have a stamped arrow pointing at them, like the one with the yellow arrow in the picture.
3 Remove the motor block and flip it over. Reflow the three solders on the opposite side of the place marked with the blue arrow.

This worked a treat for me. The tt is working perfectly. I couldn't be happier.

Thank you guys for pointing me in the right direction!
 
Last edited:
Hello all!
I figured it out myself. :)


Please open the below image for reference:

Imgur: The magic of the Internet

1 Open the back of the turntable. Unplug the connector marked with the red arrow.
2 Flip the tt over. Remove the 3 screws in the aluminium ring that have a stamped arrow pointing at them, like the one with the yellow arrow in the picture.
3 Remove the motor block and flip it over. Reflow the three solders on the opposite side of the place marked with the blue arrow.

This worked a treat for me. The tt is working perfectly. I couldn't be happier.

Thank you guys for pointing me in the right direction!
Thanks for posting this.
repair took 5 mins after reading this.
did not use my sl-5210 for many years as sometimes it went crazy and finally it always ran at full speed.
Great thanks