Mitsubishi LT-30 restoration

[hifitommy]

i haven't read all the posts but here is a link to vinylengine.com's library with downloadable manuals including the service manual:

https://www.vinylengine.com/library/mitsubishi-diatone/lt-30.shtml

 

[Aerobat]

Yea but I don't generally replace film caps, just electrolytics. Since these have continuous line voltage in them I guess they wear out.

 

[Pio1980]

The suppressors are usually film types and long lived.

 

[Ingo schwenk]

Hi,
I´m new tro this group and I own a lt30 since two weeks ago, I bought it at ebay USA and it doesn´t took the journey half around the globe to germany well. It had many transport damages and I built it up from scratch.
Now I have to replace three bulbs, then I can align and test it. Pictures coming later.

My question: Has anyone the original alignment-template and can give me the exact distance from the middle of the Center shaft hole to the top of the arrow tip "arm rest"?
I downloaded the scan on page three or four of this thread and made a drawing of it. Now I want to know the exactly distance on the original. If I have this, I will give the drawing for downloading to here.

My other LT-TTs are Sony 555, Yamaha PX 2 and PX 3, Mitsubishi LT-5V, Pioneer PL L 1000.

 

[Aerobat]

Hi,
I´m new tro this group and I own a lt30 since two weeks ago, I bought it at ebay USA and it doesn´t took the journey half around the globe to germany well. It had many transport damages and I built it up from scratch.
Now I have to replace three bulbs, then I can align and test it. Pictures coming later.

My question: Has anyone the original alignment-template and can give me the exact distance from the middle of the Center shaft hole to the top of the arrow tip "arm rest"?
I downloaded the scan on page three or four of this thread and made a drawing of it. Now I want to know the exactly distance on the original. If I have this, I will give the drawing for downloading to here.

My other LT-TTs are Sony 555, Yamaha PX 2 and PX 3, Mitsubishi LT-5V, Pioneer PL L 1000.

You don't really need the template, you can eyeball it or use a square. Just get the arm 90 degrees to the rails.

 

[Ingo schwenk]

Hi all, reviving this thread since I just finished the resto of an LT-30 I originally thought was a parts unit.

A buddy who frequents this site brought it to me for repair. It had the following issues:

• Dead electronics
• Seized tonearm height adjustment and grinding gears inside
• Missing counterweight, bottom, and accessories
  
• Trashed Dustcover
• A corner of the plinth bashed in.

Other than these, it was perfect! I told him I couldn't do anything with it. Later, when my pristine LT-30 starting having issues, I bought it from him for spare parts. Later, I started digging:

Here was the cause of the dead electronics, this is a power transistor. A quick resolder brought it to life.

Upon disassembling and un-seizing the tonearm height adjustment (solvent and blunt force), I found that a bent brass shaft, probably from a shot it took, was causing the height adjustment gears to grind. Once straightened it worked again. So things were looking up all of the sudden.

I did a half-assed plinth repair with wood filler, which passes the 5-foot test. The dust cover was sanded with 4 grades of sanding sponges then polished with a buffer. I also did a full recap while it was apart.

As for the counterweight I had to get creative as these are rare. The stock item is isolated on rubber, so I went to the hardware store and came back with a handful of grommets and nuts.

The grommets slip tightly onto the tonearm stub, then get a coat of silicone grease.

The nut threads smoothly onto the greased grommets. It needed a lot of extra weight, these are stick-on lead. It's now a perfectly functioning and isolated counterweight.

Results: (the plinth repair is to the lower left corner)

Now I'm torn between having parts insurance and selling it to a good home! Anyway, another abused one saved after a ton of work.

I can't see the pics. Can you please provide them again?

 

[Ingo schwenk]

You don't really need the template, you can eyeball it or use a square. Just get the arm 90 degrees to the rails.

Hi,
but I want to have the original distance for building up the template.
So, if there is someone wither the original template, please provide me with the exact distance.
Thank you.

 

[Pio1980]

Hi,
but I want to have the original distance for building up the template.
So, if there is someone wither the original template, please provide me with the exact distance.
Thank you.

Iirc, it is 50mm, stylus stone tip to headpiece collar, it should be in this thread somewhere.
It will be whatever is consistently tangent on a set radial line outward from the spindle center to the right.
For neutral arm alignment in play, adjust tracking tangency on the carriage for the arm gimbal to be perfectly square in the carriage when tracking a record.

 

[Ingo schwenk]

Hi Pio,
thank you for your reply.
But I don´t want to know the overhang-distance, but the distance on the tracking angle adjustment gauge.
Please see the attached file. I´ve drawn it for use by anyone here, but I´m not sure, if the distance given in the gauge is the exact value from the original gauge.
So i want to get the correct distance from one who get the original gauge.

 

[Aerobat]

It's about 207mm but that measurement doesn't matter so much. I scanned mine, printed it using Adobe reader DC at 100% scale, and verified the measurements of the printout are correct.

 

[Aerobat]

Also, the distance you are asking for can be measured on the turntable!

 

[tcalhoun8]

Greetings all, I've followed the posts on this site with great interest. I'm the original owner of an LT-30 from the early 1980's which still looks great and has all parts/tracking guage/manuals. Back in the day, it got a lot of use, but less so in the digital age. Now that I'm getting nostalgic, I really want to get it working again and hook it up to my Haffler 220 amp and pre-amp (that still works) that I put together from kit form ~35 years ago. The good news: the platter turns on and rotates; the prisim light(s) work, the tone arm will traverse the platter going forward and in reverse. The bad news: the tone arm hums when asked to go up or down (it does neither), perhaps there are other issues.

Reading through the posts, it looks like there would be some intricate tonearm work, and probably some bulb replacement (at least) and who knows if there are other required parts. At this point, I don't feel like I have the ability or equipment to give this a proper try. My question is, does anyone know of anyone in the Boston, Massachusetts area who might be able to take a look at this? Obviously I'd be paying. Alternatively, what equipment might I need to try and do it myself? My technical abilities are only so-so. Last option is to sell, but I don't want to go down that road. Thanks!

 

[MRL_Audio]

The tonearm hum maybe coming from the mute switch which is probably moderately corroded. A little Deoxit may fix that. The service manual is available at Vinyl Engine. Need to be a member to download but it's free to join. The bottom is simple to remove to have a look around. If you are at all mechanical you should no issue here. There are more knowledgeable folks here that will more than likely chime in to help. I knew nothing when I purchased mine but have done bulb and belt replacements as well as make other adjustments. Feels great everytime I look at it to know "I" fixed it.

 

[jkrichards]

It sounds like your tone arm belt is bad. The hum your hearing is the motor spinning. It will not stop spinning until you power the table down. When you power it back up you will not hear the motor spinning until you tell the tone arm to move up or down. If you can't fix it I would fix it for you as you are not too far away. Also I do a mute bypass and carry a wire outside of the turntable with a 1/8th" plug for an external mute circuit. I build a very high quality mute box that connects between your pre-amp and amp. It works perfect and has no effect on the sound quality and you can use any cartridge pre combination.

 

[perryinva]

I see no one ever answered spoonys issue from back in 2015 about the arm not moving back to rest on its own w/o a nudge or advancing when the FWD/REV buttons are held down. In case anyone ever comes across this thread looking for an answer to the same problem, the problem is almost always too tight or heavy a belt. The replacement LOOKS like it should work fine, but is won't. A lighter and easier belt to turn and everything will work as it should. Exact same issue (not size) for the LT-20/22 and 5V.

Also for jkrichards, what is the reason/advantage of an external mute box?

EDIT: Found this in my own post on page 14. The traverse looks the same as the LT-20, but the lift belt appears smaller.

EDIT: Neither belt is the same as the LT-20. The drive belt is larger, and the lift belt is smaller. Found the post where the sizes are listed as SBS3.1 and SBS5.1. I used SBM5., and SBO3.2, work perfect. (I had a bag of assorted belts and found the 2 that were perfect, not too tight, not too loose, so but their cross sections are not SBS).

SBM WILL be too heavy though. I know I had to go back in and change that belt out for an SBS or SBO later.

 

[jonboy55]

I am working on a Mitsubishi LT-30 turntable.

I'm the original owner and hadn't used it in about 15 years.

When I first powered it up I heard the whine of the motor and the tonearm wouldn't lift nor would it move horizontally. I purchased and replaced both the horizontal and vertical belts.

Now the tonearm will cue up and down and it will move horizontally across the record. It also can sense the difference between a 33 and 45 rpm. When I press start, the tonearm will move to the correct lead-in position of both a 33 and 45 rpm record.

Now for the problems:

1. At the end of either a 33 or 45 rpm record the tonearm will not lift or return. The only way to return the tonearm to the arm rest is to press the stop button.
2. Tracking Error Indicators - at all times the left and right arrows are illuminated. The "I" mark is never illuminated. All other lamps on the indicator P.C. board work correctly.

I read most of this thread and replaced the 3 lamps on the lamp P.C. board - LA101, LA102, and LA103. Just to be sure I replaced lamp LA202 (the "I" mark indicator).

I did notice that lamp LA103 (end light source) is always illuminated when the turntable is in the "on" position. I've never seen LA101 or LA102 illuminated. Is this normal?

Both prism lamps are working.

Can anyone suggest what I should check/replace next?

I would also like to thank everyone who has contributed to this thread. It has been extremely helpful.

 

[MRL_Audio]

I’ll continue to follow this. However with a greater level of anticipation since the tracking lights on one my units do the same as yours.

 

[Pio1980]

Mine also has "quirks" I've attributed to the tracking function transfer relay circuit, possibly fouled contacts, not sure.
I'd want to look at the schrematic to relate it to the two preceeding postings, but it with my TVE password is in a retired computer hard drive.

 

[bobinaz]

Hello all. I recently obtained a LT-30 and from the posts here describing problems, it looks like I have to at least replace the belts. I have ordered the 2 needed belts. The one easily accessible belt on the pulley and motor looks and feels really loose. I have been reading about the belt inside the tonearm assembly. Not the easiest to replace but doable with time and patience. I was looking at the service manual, and I can't see where it mentions the belt inside the tonearm or display it in the parts list or breakdown diagram. I haven't started taking it apart yet, waiting for the belts to arrive. Looking at the manual, "removal of the tonearm assembly" what step should I be able to see the bad, broken or gooey belt? I've read this thread and saw the pics but can't figure out exactly where that tonearm belt is. If I just have to "do it to see it" well ok.

 

[Aerobat]

Follow the service manual letter-for-letter, except it's not necessary to unsolder the wires from the tonearm base, you can put a soft cloth on the rails and gently turn the arm over to work on it. Take lots of photos so you remember where things go. It's easy to pinch the wires when reassembling so watch out for that.