Mitsubishi X-10 (MC-8000) linear tracking system

Im looking for someone with tech experience concerned with Mitsubishi's Linear Tracking turntable system
I'm repairing one for a friend and I've got most of it working excepting the linear tracking system.
It engages when you press play but instead of arriving at the vinyls edge and setting down it just travels all the way in until it can go no further and then continues to try, putting stress on the linear tracking components.
What I'm imagining is that the light sensors which determine the size of the record playing are not working, or the light sensors which tell the tonearm to set down are not working. The tracking mechanism system works by having sensors slide over a group of different slots, each slot corresponding to a record's size and when it is to stop. The circuitry around the latter sensors appears fried a bit, does anyone think that if I replaced these the system might work again?
Any help or advice would be super appreciated.

I had the same problem with mine (same turntable, but in the form of the Mitsubishi X-10 "Vertical Music Centre") not recognising the record and the arm swinging straight across. After taking the back off and having a look around, I found three LEDs on top of the tone-arm's motor had burnt out. One I replaced these, she was as good as new!

Click to expand...

I had one of these a while back and had this info in my file.

:superduper: has the service manual
http://www.analogalley.com/osccart/product_info.php/products_id/147 or the schematic is on vinyl engine

tshorba said:

I had the same problem with mine (same turntable, but in the form of the Mitsubishi X-10 "Vertical Music Centre") not recognising the record and the arm swinging straight across. After taking the back off and having a look around, I found three LEDs on top of the tone-arm's motor had burnt out. One I replaced these, she was as good as new!

Click to expand...

I had one of these a while back and had this info in my file.

:superduper: has the service manual
http://www.analogalley.com/osccart/product_info.php/products_id/147 or the schematic is on vinyl engine

Click to expand...

Wow thats so cool. Thanks. I have one here waiting to be serviced too.

I got the service manual for my Z20 system which has the same sort of setup as you mention ledmeter. Mine unfortunately has no life to the motors though
I have seen the little circuit board that has the sensors on them for the records, they appear to be two small sensors, one for each size. Do you have a probe to see if there are pulses/signals coming down the pins from the intelligent IC to the turntable ? Its about as far as I had got with mine as I didn't have the time to delve further.
Was there something specific you did to get power to your motors when pressing the phono button ?

Mine is almost fully working, it needs new needle for sure.
heres free service manual if someone need
http://www.sendspace.com/file/zi3ea5

tshorba said:

I had the same problem with mine (same turntable, but in the form of the Mitsubishi X-10 "Vertical Music Centre") not recognising the record and the arm swinging straight across. After taking the back off and having a look around, I found three LEDs on top of the tone-arm's motor had burnt out. One I replaced these, she was as good as new!

Click to expand...

I had one of these a while back and had this info in my file.

:superduper: has the service manual
http://www.analogalley.com/osccart/product_info.php/products_id/147 or the schematic is on vinyl engine

Click to expand...

Thankyou so much Tshorba. I will look into it. This is fabulous news. If I cannot find out how to purchase the correct components I'll report back here.
Warren

I downloaded the service manual thankyou very much! But alas I could not locate what I was looking for on it...
But as I read on over your quote, tshorba, it seems the parts burnt out are only LEDs? I guess they are simply to transmit light for the purpose of being detected when the LED and sensor pass over the slots.
here are some pics.


Presenting the linear tracking system. You can see the tonearm ascend/descend motor and the metal plate with the guide slots.

Here we see above the metal plate where the LEDs are supposed to be; they are pretty burnt out! Sadly the heat from this LED fire left a warp in the top of the unit.

And finally the sensors below, they appear undamaged. It's all starting to make sense now. so; if I replace the LEDs it should potentially work again! I love fixing things!
Question: What size LEDs ought I use? Little ones? Regular size ones like in a VU meter?