Renfield72
New Member
Has anyone documented made a dummies version of how to get into the tonearm drive belt? Service manual is too blurry.
Mitsubishi LT-30 restoration
- Thread starter kotofei
- Start date
I believe it was in one of my posts at the very beginning, perhaps in a short form.
EDIT: It's in the post #2. IIRC it's less difficult that it seems reading the SM and you shouldn't desolder anything. IIRC (again) after you remove the tonearm carriage, you can see a belt. You'll have few wires going from carriage to the TT body but they wouldn't interfere with belt change.
EDIT: It's in the post #2. IIRC it's less difficult that it seems reading the SM and you shouldn't desolder anything. IIRC (again) after you remove the tonearm carriage, you can see a belt. You'll have few wires going from carriage to the TT body but they wouldn't interfere with belt change.
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Now that is clever. I'll try that for my LED conversion in the instrument panel of my british car (even with the panel lit, you can't read it in pitch darkness). I would think you'd have to use 3mm LEDs to fit in place of the 'grain of rice' incandescents for the prism.
I need to replace the tonearm lift/lower belt.
Old Vinyl
New Member
New LT-30 Problems
I've had a new LT-30 for a few days now. When I first tested it, the tone arm would not go up and down but could hear the motor working and the arrows on the display were operating correctly. After disassembly, I notice the arm lift gear was not meshed with the rack, the motor was activating the switches correctly but the gear not moving. I reset this and installed a new belt since the old one was not good with the belt goo on the small pulley. Cleaned everything and installed the belt.
Now, everything works except when the cartridge is fully lowered at the beginning of the record, the tone arm begins moving too and reaches the end of the record and returns. I noticed the tracking servo light is on all the time pointed to the left.
Question, is this problem caused a burnt out tracking light bulb up inside the tone arm assembly?
I've had a new LT-30 for a few days now. When I first tested it, the tone arm would not go up and down but could hear the motor working and the arrows on the display were operating correctly. After disassembly, I notice the arm lift gear was not meshed with the rack, the motor was activating the switches correctly but the gear not moving. I reset this and installed a new belt since the old one was not good with the belt goo on the small pulley. Cleaned everything and installed the belt.
Now, everything works except when the cartridge is fully lowered at the beginning of the record, the tone arm begins moving too and reaches the end of the record and returns. I noticed the tracking servo light is on all the time pointed to the left.
Question, is this problem caused a burnt out tracking light bulb up inside the tone arm assembly?
62sunbeam
Raconteur
Old Vinyl
New Member
Tracking Lamps
Looking at the disassembly instructions in the service manual, it says to unsolder the 5 lead wires attached to the muting board. It appears this needs to be done to remove the tone arm and access the lamps. Please confirm. I'm nervous about doing this and having to re-solder and not damage anything. Oh well, thats what I get for tackling a new project. I wish the lamps could be tested without disassembly, but it looks like they are wired in parallel so testing the red and purple wires where they terminate at conn-5 would only show an open circuit if both bulbs were burnt out. I will clean and double check the plug at conn-5 just to make sure its not a bad connection.
If any of the tracking indicator lights on the display are burnt out, would that affect the tracking operation?
Looking at the disassembly instructions in the service manual, it says to unsolder the 5 lead wires attached to the muting board. It appears this needs to be done to remove the tone arm and access the lamps. Please confirm. I'm nervous about doing this and having to re-solder and not damage anything. Oh well, thats what I get for tackling a new project. I wish the lamps could be tested without disassembly, but it looks like they are wired in parallel so testing the red and purple wires where they terminate at conn-5 would only show an open circuit if both bulbs were burnt out. I will clean and double check the plug at conn-5 just to make sure its not a bad connection.
If any of the tracking indicator lights on the display are burnt out, would that affect the tracking operation?
Old Vinyl
New Member
Tone arm tracking sensor bulbs O.K.
I finally figured out how to get the tone arm separated without de-soldering any lead wires. Clipping a plastic tie wrap holding the wire bundle under the main body, I was able to coax the wires and muting switch enough to withdraw the tone arm and inspect the bulb holder. I turned on the power and both tracking bulbs work!
Looking closer, there is a "holder-L" #14 on the diagram. It is attached to two hex studs that are attached to the upper part of the tone arm. This is suppose to swivel as the tone arm moves but appears the screws are broken off in the upper part of the tone arm. I can see the broken screws when I rotate the tone arm swivel. Now I'm really up a creek with no paddle. Guess I can try to remove the broken screws but I most certainly will have to remove the cartridge lead wires to do this.
This must have happened during shipment with the tone arm banging around from sellers poor packaging.
I finally figured out how to get the tone arm separated without de-soldering any lead wires. Clipping a plastic tie wrap holding the wire bundle under the main body, I was able to coax the wires and muting switch enough to withdraw the tone arm and inspect the bulb holder. I turned on the power and both tracking bulbs work!
Looking closer, there is a "holder-L" #14 on the diagram. It is attached to two hex studs that are attached to the upper part of the tone arm. This is suppose to swivel as the tone arm moves but appears the screws are broken off in the upper part of the tone arm. I can see the broken screws when I rotate the tone arm swivel. Now I'm really up a creek with no paddle. Guess I can try to remove the broken screws but I most certainly will have to remove the cartridge lead wires to do this.
This must have happened during shipment with the tone arm banging around from sellers poor packaging.
Pio1980
AK Member
Part #14 "holder L" is the differential shutter for tracking correction, no way to know for sure how the parts #101 screws got broken as the coupling studs on the arm gimbal limit movement. You may have to remove the arm/gimbal from the carriage base after unsoldering the 5 wires to access the broken parts in the coupling studs which do unscrew from the gimbal tho' shown as part of the gimbal, please see my portion on rewiring the from this thread for some guidance and pix.
I didn't find a pic for the next step. Looked.
I believe your next step would be to slide the steel pole out of the way, remove the L brackets from the base of the tonearm, and then pull the tonearm out. Then you should see the tonearm lift belt (or at least the pulleys) inside of the tonearm - visible in picture #4 of post #2 in this thread.
Pio1980
AK Member
I think the brass threaded coupling studs may be broken off at the gimbal, it'll have to come apart/off after desoldering the 4 signal and 1 ground wire from the muting switch terminal board.
Here's one stud in and one out;
Both in;
Here's where the wires are soldered, route them this way when restoring;
Rerouted shortened carriage signal & ground wires;
Ah, so i had to loosen the two tiny allen hex grub screws to slide the metal pole out. Now, i'm struggling to get the tiny belt on. Any tips?
Pio1980
AK Member
First I'd recommend running just a droplet of light machine oil on a toothpick onto the motor shaft next to the shaft bushing in the motor and also the worm bearing shaft bushing and the gear shafts with the 'C' clips, perhaps a bit of light grease or Vaseline on the visible gears. Use a bit of liquid lighter fluid on bits of paper towel to clean up oil/grease that gets where it shouldn't go and clean the pulley rims as best as possible with the lighter fluid/paper towel bits.
Make a hook-ended thingie from a paper clip, work the belt onto the larger pulley and use the hook-thingie to work the belt onto the small motor pulley.