Sanyo TP-600 SA shaking problem

Hi all,

I've recently acquired a belt-driven Sanyo TP-600 SA deck and have been slowly refurbishing it. It has a shaking problem that seems to have gotten worse in the past few days. I'm attaching a couple pictures so you know what kind of deck we're dealing with here.

Short version
When I turn it on and play a record, everything works great for about 2 minutes, and then the whole part of the the turntable that rests within the plinth (the main plastic part that has the engine, the platter, tonearm, etc, and that rests on springs) starts shaking. This causes the tonearm and the headshell to shake left/right within the grooves and messes up the sound (as if the platter was slowing down, then going faster, and so on). Once this happens, there's nothing to do. Turning it off/on doesn't change anything. I basically wait until the next day, and then when I start over the shaking happens again after 2 minutes of listening.

Long version
There are a few elements to take into account:
- when I remove the platter and start the turntable, there's no shaking at all.
- when I leave the platter but remove the mat, I can see the engine shaking left/right, as if it were having a hard time driving the belt. This seems to be what's causing the whole thing to shake.
- I recently changed the belt (FRX25.0) and put in a new M97xe cartridge. The belt is the one that all the websites recommend for this TT and seems to be the same size as the old one.
- the shaking problem was happening every once in a while before I changed the belt, but it wasn't bad. As in: it'd happen twice a week, and I'd just turn it off, change the record and everything would be fine. It seemed to have gotten worse (and would systematically happen after a few minutes of listening) when I put in the new belt. Thinking the new belt could be too tight and was causing the problem, I changed it back to the old belt, but the shaking was still happening. I've been alternating between the old & new belts, but the problem seems to be just as bad with both.

Any help is appreciated! Thanks in advance,

Thomas

I would suspect motor mounts and/or motor bearings.

Steve

SteveA said:

I would suspect motor mounts and/or motor bearings.

Steve

Click to expand...

As unlikely as it may seem as a cause, I agree with this. I just had a CEC made Rotel that is very similar to your Sanyo, which is also CEC made, that had the same symptoms. It drove me nuts until I took the motor apart and cleaned and relubed the bearings.

Is the front of your table sitting quite a bit higher in the base than the rear or is that an optical illusion?

Thanks for the replies Steve and Gary.

Gary, I think it's just an optical illusion.

Ok, well, I guess I'm taking the turntable to a repair place then. I don't have the skills to take the motor apart.

I agree with 12ax7 as I had a similar problem with a similar table but it was not quite as serious either. I don't recall having to do a full dis-assembly. Can you take a picture of the motor on it from inside? It's possible that we can direct you how to oil it yourself.

You can get inside the table to see the motor by loosening the screw immediately to the right of "qualified service personnel" (yeah right) and sliding it in toward the spindle. There should be another of these screws near the back, so do the same there. Those screws move some clamps away from the wood plinth and allow the metal bits to be lifted up.

Absolutely try to oil it without disassembly first. I just like to take things apart, but in my case the bushings were badly caked up and needed cleaning. Try the easy way first. One thing I've noticed about those CEC tables is that as much as they look similar, from brand to brand, at first glance, they often have quite different motors and mechanicals in them. A pic will help.

I was thinking of that sliding screw when I mentioned the apparent illusion. I've seen them and the red transport screws misused.

Hey there Montycat,

I was actually just reading your thread about the shuddering PL-A35! Ok, thanks to your directions I was able to access the motor. Here are three (lousy) pics I took - I can ask my lady for help later to take better pics while she holds the turntable. Let me know your thoughts.

Thanks for the help!

Thomas

Ah, Gary, saw your post right after replying to Montycat.

What kind of oil can you guys recommend? Gary, How do I oil the motor from the outside? I haven't been able to figure this out, even though I have a copy of the owners manual for my TT as well as a service manual for a very similar TT (the TP 625).

am thinking the platter could be binding or the bearing is worn maybe .

I am at work, so can't help too much more now but you are looking at a motor than can be worked on fairly easily. The motor is somewhat similar to this one but does not even need to be taken apart as much if you can get oil in through a narrow oiler tube. You may just need to back the 2 screws (one with the ground wire) off near the center of your second pic.

I use synthetic 10w30.

http://www.afishneedsastereo.com/2013/11/from-66-23-to-33-13.html

I'm sorry. I guess I wasn't very clear. I meant the outside of the motor. You have it far enough apart to do the job. Just oil the areas where the motor shaft enters the motor bushings, they're somewhat hidden but visible. Use a light weight machine or motor oil, not a penetrating oil.

Is this like phone tag?

So where was I?

This piece (from a Dual motor) is similar to the top and bottom of your motor. The bearing is kind of a ball joint and the 2 have to not only be both lubed but in alignment with each other. It is possible that loosening the 2 bolts will help with both.

Top bearing by Buhduh, on Flickr

Oiling bearings by Buhduh, on Flickr

On this Dual I did have to take it apart. I'm only showing it to demonstrate where the oil goes not suggesting you have to go this far. In many other motors you can only introduce oil from the top but this needs it in both places ideally. In your case you have to get in between the grey bearing cup and those fins.

All right! I'm 2 records into it, and so far it sounds good!

As suggested, I introduced a few drops of oil in both places and loosened the two bolts. Seems like it did the trick. Thanks so much for taking the time to guide me through each step. Saved me a trip to the repair joint, some bucks, AND I've learned a few things in the process. Killer.

Excellent!

Make sure those nuts are on snugly so they don't vibrate off. They originally had some thread locker of some sort. Loctite 242 (the blue stuff) would not hurt, or a dab of nail polish on the threads would be fine.

Very nice OP glad you got it working on your own. I learned a thing or two as well thanks Montycat for the tutorial.