So I have a Marrantz LV510. It plays CDs fine, but when it tries to play a LaserDisc, it just vibrates violently (with every disc I've tried). I've opened up the top and watched the disc spin and as it turns out the disc also wobbles. Anybody know what might be wrong with it?
(sorry if this should've gone in the Technical questions section)

I've found this happening for a couple of reasons, once so bad that a disc edge hit the player body and cracked into pieces. The upper clamping device maybe loose or worn, or even broken, in such a way that it does not clamp properly and steady the disc when spinning. Another thing I've seen less commonly is the spindle motor worn out so it wobbles under the weight of the LD. The CD isn't heavy enough nor wide enough to cause the problem to be apparent.

I'd check out the upper clamping spindle first. Also see if you can actually move the lower spindle and stem back and forth by hand to see if it's loose within the motor. Make sure there isn't any piece of either the top or bottom clamping material that came off so as to cause unbalanced weight.

Actually the best test for motor bearings are the 5" CDV's as they spin the little disc fast for video. CD's just turn too slow to show motor issues like this. Motors just going bad will scream with the CDVs while still pretty quiet with 12"LDs. rixrex is correct. The function of the top clamp is to securely hold down the disc on the lower spindle motor clamp surface. Sounds like a motor bearing issue.

thanks for the replies!

so I removed what I believe to be the upper clamp and it does move in 3D by hand (i can move it up and down as if to clamp a disc and side to side, which I presume is what lets it wobble)


also, when I was taking off the player's cover I heard a rattling and it turned out to be two pieces of broken circular white plastic and a tiny metallic marble


so what should I do now?

It looks like you have a broken upper clamp bearing ring. Those pieces appear to have come from the upper clamp. It's a bit hard to tell from the photo, but they might have been part of that upper assembly. But still you should check to be sure that there's nothing broken or missing from the lower spindle.

If you can take apart the upper clamp assembly or see if those pieces seem to fit in place on the upper assembly somehow, you may find where these parts came from, that is if they are not from the lower spindle. This is likely what's causing your problem. Although I'm curious as to why it broke that way.

You'd need to get the replacement part. I believe the Marantz LV 510 is a Pioneer clone, though I don't know which one. It looks like it might be a clone of the CLD-D503. The Marantz LV 520 is a clone of the Pioneer CLD-D504.

If it's a Pioneer clone, the part may be available from Pioneer, or from someone with a parts player.

Can you get a photo of the back of the player and maybe a couple of pics of the internal parts to help see if it's a match to the D503.

Forgot to ask, did this player come to you this way in a recent shipment, or purchase, or have you had it a long time?

I got it a month or two ago like this on eBay

so I found another piece (looks like the other two) and a much smaller piece jammed in the upper clamp (the tiny one, not the third circular piece), when I tried to connect one of the bigger (though still small) circular pieces to the clamp it attached perfectly

The lower clamp looked fine as far as I could tell (as in it didn't seem to have the same problem(s))

here are pictures of the back



(MFD.JULY 1994TP)

here are a few of the inside




(My camera is a 3DS, so I'm limited to 640x480 JPEGs)

EDIT: Is it possible to use the clamp from another player? or are clamps very unique to a player?

There are a total of three steel balls and the white plastic pieces form a complete ring and there are screws holding it together. There are more parts inside somewhere. If you don't get offers from others I do have extra upper clamps and can sell you one.

Kurtis
kbahr@comcast.net

That does look like a D-503 pioneer clone. I've seen that same type clamp on others.

Probably a good idea to get it from Kurtis, since he has them, rather than look for a player that has it. Unless you know of a place that has a bunch of junked LD players.

If nothing else works, try turning it upside down & shaking it to get the other parts out. You don't want a loose ball bearing shorting out delicate circuitry, assuming that hasn't already happened. A magnet might help, though, before you get to that stage.

That's right, I didn't think about the ball bearings left inside. Good idea.

I'm still wondering how something like that happened. I've seen the upper clamping device get worn and loose but never saw the breaking of the ring that way.

I always flip the players all directions and shake them when parts are inside. May be OK if you keep the player stationary but if you ever travel with it or ship it that is when you take a big risk that it be be jammed by the parts or the bearings causing shorts.

I shipped him the complete top assembly today so he'll know what to look for.

I think it might be because it was shipped with an Aladdin disc inside

I got the replacement clamp from Kurtis today and the player now works perfectly, thanks for the help guys

Great to hear. Another player saved from the trash-heap. Somebody else would have tossed it.