Any LAB 400 owners? Need some help.

[RWB]

I have a LAB 400 that has a strange problem and wondered if anyone might have some insight.

 

The turntable seems to work pretty much perfectly.

 

1. It turns on

2. all the auto functions work

3. There is ZERO noise coming from the turn table while spinning

4. Records seem to sound good to great (compared to a new-ish Rega RP3 with good cartridge I have, slightly different flavor of sound but nothing you'd notice horrible)

5. Speed is pretty stable after it warms up and runs for a little bit.

 

So what's the issue? Well if you touch the platter with very little force it will rock back and forth in every direction as if the platter is floating . So much so it will easily contact the plinth any where you touch it. While spinning it is slightly out of true (a very minor wobble but nothing I'd consider way out). 

 

Since I don't own another LAB 400 nor have I seen one in person I have no idea if this is part of the design?????? Doesn't seem like it as I've never seen anything before like it. My other direct drive table that were VERY similar in design in the past never behaved like this, the platters were rock solid.

 

I've not completely disassembled the table yet but my first thought was the motor was loose/not connected to the plinth. Doesn't seem so, I remove the platter and the motor housing itself seems solidly mounted. There's a hair of up/down play on the spindle and what seems like some lateral play which is probably the issue. With the platter on it is solidly connected to the spindle which also deflects when you rock the platter back and forth with just a touch anywhere near the edge.

 

Before I take it apart I'd like some input as I have no idea what I am supposed to be looking at. My wild guess is that the spindle/flywheel/magnet component rides inside/on some kind of bearing that is broken, misaligned, not seated correctly, loose, etc but... I have no clue what the behavior should be or what I need to do to fix it. The problem with my theory assuming they are not all like this is --- if the bearing is broken/not seated well or something along those lines wouldn't it be making a lot of noise or ANY noise and have issues with speed etc????

 

Would love someone that knows this table's help.

 

Thanks

 

RB

[RWB]

Just wanted to post an update for those that suffer this issue in the future.

 

To answer some various points above:

 

1. NO, the platter is not supposed to rock/wobble if you lightly touch it anywhere.

2. YES, it was working perfectly except for this flaw which was absolutely not affecting the sound on flat/non-warped records or lower volumes (my room is not the best so stability of the platform is not completely isolates. Yep it is a problem.

 

Given I've had this thing sitting around for more than a year without really using it I decided to take it completely apart and figure out what was going on. Here's the low-down...

 

The spindle was fine, the platter was fine, the motor was fine... My guess that it was the bearing proved to be wrong, that was perfect as well.

 

The actual armature (or whatever that interior part with the 16 wound coils are that surround/contain the bearing was "loose" in the metal shell housing. The problem with this is that that part is secured to the metal housing(well) with three tiny little screws that you CANNOT get to because a circuit board is in the way that is soldered to the motor component board on the other side. I had to care fully move it slightly out of the way while using pliers to tighten the screws from the side as good as is possible. Really poor choice to solder the board via 10 thin uninsulated stiff wires while covering the motor mounting screws...

 

This is a fantastic table but anyone that is having this sort of issue the answer is simple but not easily dealt with.