How do i fix a record size sensor on my 1985 Tecnichs turntable ?

Technics SL-QD33 doesn't turn - Vinyl Engine

www.vinylengine.com/turntable_forum/viewtopic.php?t=28381

Jun 3, 2010 - 15 posts - ‎3 authors
It powers up, lights come on but the platter won't spin. ... However when I press "start", nothing happens and the platter won't spin when ... the arm towards the record without pressing the "start" button. ... SL 7, SL-10... and / or any of the fully automatic Technics turntables using optical record detection......etc Marantz 6300 question...
15 posts
Nov 21, 2009
Dual CS505 turntable won't auto-start
13 posts
Aug 16, 2009
More results from www.vinylengine.com

Help!! My Turntable won't spin - AVS Forum ' Home Theater ...

www.avsforum.com/.../1316271-help-my-turntable-won-t-spin.html

18 posts - ‎7 authors

Hi, most likely the auto function needs resetting. With the power off turn the platter manually clockwise a dozen or so times. Power up and play. Cheers john.

I have a 1956 stereophonic Motorola record player, and it turns off right when I press "on" I noticed that the record speed was 33 1/3 I used 33. Does this make a difference??

See what kind of arm position sensing elements are used in your turntable (micro switches, optics or possibly other) and check if they work correctly - sometimes a microswitch can be damaged or have oxydized internal contacts or a badly soldered / broken wire and it will not function properly, causing the unit to stop automatically, the same might happen if the sensor is of optical type and there is some dust or broken wires or if the emmiter or sensor is damaged. Also, it could be a problem with the part that activates the switch / optics, it might be displaced or damaged.

If all sensors / switches seem to work well, then check the section which has wires going to those sensors / switches, it's the next probable location of the fault (it might be an electronic controller so there could be damage to some components, broken wires, dirty connectors or bad solder contacts).

It could as well be something else in the mechanisms, wiring or electronics, i just suggested a few things that might cause the malfunction you described.

Hope you can get it fixed.

regards

3rq8 (Triarcuate)

There is 33and 45. that's the size of the record.There should be a level to change from one to the other.

There should be a record size selector switch somewhere. It will move the arm to the positions for 12inch 7inch and 10inch records. It must be set to 7inch or 10 at the moment. For 33 it should be on '12' and for 45 on '7'.

I do not quite understand your description. However, the motor switch is underneath the deck and is very sensitive to adjust if you have to.

Try starting from scratch with no record on the turntable, the protector over the stylus. and the arm lifted with the cue button. The motor should not be running.

Gently move the arm towards the platter. The motor should start up.

Continue gently moving the arm across the platter slowly until you hear a slight clicking noise.

The arm should try to lift (it's already up) and return to the rest - it will stay up, of course.

After one more rotation of the platter the motor then switches off, or is supposed to at least, by a cam under the platter. You should hear the click as it does so.

It is all a matter of adjustment, and any knocks or bangs the deck may have had may have changed the set-up.

The STOP button you mention is so that you can start the arm lift- and -return cycle at any point on the record. It is not a switch.

Are the record size tabs sticking up through the turntable platter cover? They sense the size of the record being played and adjust the run out distance for either 45 or 33 rpm records.

I had the same problem with the arm constantly starting and stopping, and the suggestion above works. Despite, I was a little confused on how to do it. Here's what I did in detail:

- Remove the turntable mat.
- Unhook the belt and remove the turntable platter.
- Once the platter's removed, you should see two plastic white gears in the middle. Rotate the center gear clockwise until its tab hits the larger gear. The center gear should move freely and without resistance until you hit that gear.
- Put the platter back, making sure to re-hook the belt around the spindle.
- Put the mat back.

After that, you should be set!

HI...
One or two mechanical linkages inside have "let go"
Denon is good stuff. Depending on where you live I might be able to suggest someone to fix it.