Location: Central Oregon
Beogram 1900 possible motor issue
28 replies
Here a pic with the platter on. There is a little crack on some rings, but seems to still be good. I'll leave that alone. The tonearm and top plate are in good shape. Login to view image
Hello, I'm new to this forum, but not to audio forums. Now that I have a couple of Beograms, I figured I should get on this forum and learn a few things, and hopefully be helpful at some point. I got into audio back in the 70's as a teen. Mowed yards to earn money for my first system. Right after college, I bought a Beogram 1700/1800 (can't remember which one) with a MMC2 cartridge. I was asking myself if I was nuts, when I heard that the cartridge would cost the same as the turntable. Today, I have a RX2 and a 4002 that needs service. But today, I am here to get help a local elderly gentleman who brought his 1900 to me. It wouldn't power up. It has sentimental value to him, so I'd like to get this working for him.
What I can tell you about this 1900, is it's clean. I was told this didn't get a lot of use, and it looks like it. I used the MMC 6000 from my 4002. I don't know if that "should" work, but I wanted something on there, and the MMC 6000 has the same mounting style. He can't find his MMC 4000, so I'm going to get one from someone I know that rebuilds these. But for now, I'm hoping I can get moving on this to make sure the table will work before buying a cartridge.
The original problem is the platter won't spin. The power cable is fine. I get current to the motor. In fact, when I push the copper colored washer (part 109 in the service manual), I can feel some vibration telling me current is getting to the motor. For this reason, I assume the motor needs to be cleaned and lubricated. But I have read some posts online about the motor in this not being so good. I'm hoping it is useable.
I have learned over the years that when I work on gear, there are always surprises. Since I'm trying to get this done in the next few weeks for this gentlemen, I figured why not ask first to see if anyone has any tips and tricks on things to focus on, try, and/or avoid. I have the service manual, but it is more useful as a parts diagram and schematic.
Location: Central Oregon
Can you rotate the motor by hand?
If not - take it apart, clean the spindle and replace the bearings.
Martin
I would start with the power supply and check if you ar getting the full 12.5V when the motor is trying to run. I would also consider replacing C1, C3, C4, and C5.
I appreciate that Mark, thanks!
I'll dig in tomorrow. If I don't have the right values on hand, I'll have to order, which means it could be a week to get those back, installed and tested. But I will update this thread with my status as it changes.
Location: Central Oregon
This is an odd duck. I was looking at the linkage, and the +/- Turn dial. Adjusted that and the motor slowly stars to spin. In slow motion, the tonearm swung into place. The speed of the motor slowly increased through the process, but still not fast. But it was spinning, so maybe I just need to service the motor for good measure.
Is there a "best" way to service the motor? As in, I can remove the bottom cover to access, but it is preferable to pull the entire assembly off?
Location: Central Oregon
Unless the spindle runs VERY freely by hand (read: run down 5-8 seconds or more), it will need service.
Yours will, by the sound of it.
Martin
Bingo! It moves only when I move it. There is no play, or spinning on it's own once I let off.
Thanks! I'll get that serviced. I have a synthetic lube called Super Lube that I normally use. I assume this type of motor is ok with that?
Location: Central Oregon
Motor service
I have three pics here as reference. It may help someone else since I can't find many pics of a 1900 motor.
There is a sintered bearing in the cover with a plastic plug on the outside. I am guessing there is no harm in pushing it out from the bearing side.
There is an oily substance covering the housing the motor shaft sits in. I am guessing that should not be, and that it simply migrated over the years from the only spots that should be lubricated, the bearings. Am I wrong?
Since the service manual doesn't address removal, I am also guessing the motor spindle needs to be pulled out from the top, after removing the idler wheel, and it looks like removing one motor spring will be enough to clear the flywheel
Location: Central Oregon
Just adding oil in "free form"/ as drops, won't provide a lasting solution.
It will be pressed away as the motor runs.
And only few synthetic oils have the right additives for running with the metal alloys used here anyways.
The bearings are sintered. They will need oil infused into the pores in the
metal material from where it is pulled by capillary action when the spindle rotates.
Reoiling can be difficult seeing as the remains of the old oil needs
to come out first in order to infuse new oil.
Best and easiest is to replace the bearings altogether.
New bearings here, correctly oiled.
Your bearings may - or may not - have an additional flange, which is of no practical importance here.
Martin
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