Mitsubishi LT-20 tonearm base tracking issue

[csteele2144]

Hi Guys,

Looking for some help with an LT-20 I picked up on craigslist as I'm somewhat new to TT repair. I read through the LT-30 but didn't see my issue addressed in that thread.

I've performed all the tone arm tracking, height, and weight adjustments, but I have an issue when records are playing. All of the buttons work, the left and right arrows move the tonearm the full range. The start button move the tonearm to the correct position and lowers it to the record and the stop button lifts and returns it to the rest.

My issue is that the tonearm base doesn't seem to be tracking to the left when playing a record. It will play roughly one song before the arm/cartridge can track with the record and it will start skipping.

Any thoughts?

Thank you in advance

 

[Balifly]

Hi Guys,


I've performed all the tone arm tracking, height, and weight adjustments, but I have an issue when records are playing. All of the buttons work, the left and right arrows move the tonearm the full range. The start button move the tonearm to the correct position and lowers it to the record and the stop button lifts and returns it to the rest.

My issue is that the tonearm base doesn't seem to be tracking to the left when playing a record. It will play roughly one song before the arm/cartridge can track with the record and it will start skipping.

Any thoughts?

Thank you in advance

Welcome to the AK turn table forum.

Here is a link to the owner' manual and the service manual have a look through them - "trouble shooting" section.
http://www.vinylengine.com/library/mitsubishi-diatone/lt-20.shtml

Hope you will be able find the solution.

 

[csteele2144]

Thanks for the welcome, I've found a lot of great information on this site.

I used those manuals to do the setup, but wasn't able to find any support for the issue I'm having, hoping someone else may have experienced this.

 

[Balifly]

Thanks for the welcome, I've found a lot of great information on this site.

I used those manuals to do the setup, but wasn't able to find any support for the issue I'm having, hoping someone else may have experienced this.

A short video from even a " smart phone" would be helpful.

More experience helpers would be along shortly.....

 

[vincei]

Perhaps one of the incandescent lamps controlling the tracking is burned out. These are located in the arm base. I swapped all the bulbs in mine to LEDS as I was having a similar issue.

 

[csteele2144]

Perhaps one of the incandescent lamps controlling the tracking is burned out. These are located in the arm base. I swapped all the bulbs in mine to LEDS as I was having a similar issue.

I was wondering if it might be something like that, I should have a video up shortly.

 

[csteele2144]

I was wondering if it might be something like that, I should have a video up shortly.

Video of the issue

 

[Penn42]

I've no experience with the LT-20, but I have restored a LT-5v that had this same problem, I assume the two units use the same mechanism. If they do, it's probably a burnt bulb.

IIRC in the tonearm base there is a set of bulbs that are part of size detector mechanism and a set of bulbs that are part of the tracking mechanism. I replaced mine with LED's as well and have had no problems.

 

[vincei]

Yep one of the bulbs in the tonearm is burned out. I would swap all the bulbs to LED, 3mm white LEDS are what I used. The photos show the bottom of the tonearm with the plate removed to expose where the lamps are located, the second photo shows new LEDS going in with some glue to hold them. The final result with RED disc detect LED and new aluminum feet is shown below.

Mitsubishi LT-20 Restored by mastercontrolmedia, on Flickr

 

[csteele2144]

Yep one of the bulbs in the tonearm is burned out. I would swap all the bulbs to LED, 3mm white LEDS are what I used. The photos show the bottom of the tonearm with the plate removed to expose where the lamps are located, the second photo shows new LEDS going in with some glue to hold them. The final result with RED disc detect LED and new aluminum feet is shown below.

Mitsubishi LT-20 Restored by mastercontrolmedia, on Flickr

This is extremely helpful, guess I will have to remove the tonearm... Do you have a link to the leds you used?

 

[vincei]

This is extremely helpful, guess I will have to remove the tonearm... Do you have a link to the leds you used?

I just used generic 3mm high output white that I found locally. The only thing you have to keep in mind is that you have to drop the voltage to the LEDS. Do you have the service manual? That was helpful in determining the voltages and disassembly. I think the Vinyl Engine has it. The image attached is the 3 replacement leds for the arm position with the dropping resistor in place under the shrink wrap. The 3mm legs fit perfectly. The key is to take your time.

 

[csteele2144]

Hope to have an update in the next couple of days, I ordered the replacement bulbs from amazon (https://www.amazon.com/gp/product/B00L8BR76A/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1) and picked up a soldering iron over the weekend as well. Will dissemble the tonearm Thursday or Friday night.

 

[csteele2144]

Fixed! Replaced the 5 bulbs for the tonearm tracking and alignment and its back up and running. My soldering wasn't pretty, but it's holding.

 

[vincei]

Fixed! Replaced the 5 bulbs for the tonearm tracking and alignment and its back up and running. My soldering wasn't pretty, but it's holding.

Great news! Enjoy the music.

 

[Nat]

That's a very nice table, but the method of aligning the cartridge is weird - a plastic protractor held in place by the arm base as the platter spins under it -- if you don't have that protractor, it's much harder to align. The method espoused by some, of setting the stylus on the tip of the spindle introduces a surprising amount of error since the spindle is very tall, and the arc of the arm descending puts the stylus a millimeter or two back of the correct position. And the handwritten note in the manual on Vinyl Engine is off by the width of the rubber washer -- my opinion -- there are several rather heated exchanges on the topic already up here. I used a card with a notch and a line that I moved the arm back and forth on until I was certain that the stylus tracked it exactly.

 

[rnorton]

That's a very nice table, but the method of aligning the cartridge is weird - a plastic protractor held in place by the arm base as the platter spins under it -- if you don't have that protractor, it's much harder to align. The method espoused by some, of setting the stylus on the tip of the spindle introduces a surprising amount of error since the spindle is very tall, and the arc of the arm descending puts the stylus a millimeter or two back of the correct position. And the handwritten note in the manual on Vinyl Engine is off by the width of the rubber washer -- my opinion -- there are several rather heated exchanges on the topic already up here. I used a card with a notch and a line that I moved the arm back and forth on until I was certain that the stylus tracked it exactly.

You use the plastic jig that came with the LT-20/22. You insert the mounted cart into the jig and adjust until the stylus is under the line and the cart is square to the jig. Easy peasy.

 

[Nat]

It is easy peasy if you have the protractor jig. If you don't, there really isn't any easy substitute, and I would be very surprised if they are available often even used. Hence the problem, and the various kludges.

 

[chapps]

Hi Guys,

Looking for some help with an LT-20 I picked up on craigslist as I'm somewhat new to TT repair. I read through the LT-30 but didn't see my issue addressed in that thread.

I've performed all the tone arm tracking, height, and weight adjustments, but I have an issue when records are playing. All of the buttons work, the left and right arrows move the tonearm the full range. The start button move the tonearm to the correct position and lowers it to the record and the stop button lifts and returns it to the rest.

My issue is that the tonearm base doesn't seem to be tracking to the left when playing a record. It will play roughly one song before the arm/cartridge can track with the record and it will start skipping.

Any thoughts?

Thank you in advance

Yep one of the bulbs in the tonearm is burned out. I would swap all the bulbs to LED, 3mm white LEDS are what I used. The photos show the bottom of the tonearm with the plate removed to expose where the lamps are located, the second photo shows new LEDS going in with some glue to hold them. The final result with RED disc detect LED and new aluminum feet is shown below.

Mitsubishi LT-20 Restored by mastercontrolmedia, on Flickr

Resurrecting this post for a specif problem: @csteele2144 @vincei

Have any of you adjusted the horizontal tracking angle on the Mistubishi LT-20 as per the Service Manual ? My post is here: http://audiokarma.org/forums/index....rizontal-tracking-angle.745951/#post-10114202
This involves measuring current across two points. I have tried this 3 times in many combinations but always have a "0" current. It is current in uA (microamps), and both my multimeters can do microamps. Or is it that the difference is microamps?

I am never able to read any current, so was wondering if you guys have attempted this....

Thanks!

 

[csteele2144]

Resurrecting this post for a specif problem: @csteele2144 @vincei

Have any of you adjusted the horizontal tracking angle on the Mistubishi LT-20 as per the Service Manual ? My post is here: http://audiokarma.org/forums/index....rizontal-tracking-angle.745951/#post-10114202
This involves measuring current across two points. I have tried this 3 times in many combinations but always have a "0" current. It is current in uA (microamps), and both my multimeters can do microamps. Or is it that the difference is microamps?

I am never able to read any current, so was wondering if you guys have attempted this....

Thanks!

I'll admit, I adjusted this setting once, but only because I could see it was off visually. I read the instruction manual and determined it was above my skill level and decided to do it my own way, for better or worse.

My process was to turn on the player, start playing a record, and use a small screw driver to adjust the tracking angle while it was playing. While it definitely isn't perfect, I could hear the sound change and visually see the adjustment as I turned the screw. I'd be interested in the correct way to do this if someone can explain it to me.

 

[chapps]

I'll admit, I adjusted this setting once, but only because I could see it was off visually. I read the instruction manual and determined it was above my skill level and decided to do it my own way, for better or worse.

My process was to turn on the player, start playing a record, and use a small screw driver to adjust the tracking angle while it was playing. While it definitely isn't perfect, I could hear the sound change and visually see the adjustment as I turned the screw. I'd be interested in the correct way to do this if someone can explain it to me.

Thanks!! Very useful info, since I don't feel totally stupid for trying the service manual method. My arm looks very aligned....but I get paranoid sometimes!! Especially since I fidgeted with the electronics. But since many guys do this manually, I think I am good.