On my Panasonic LX-900, when I put a disc in and it first starts to spin up I notice what looks like a rippling interference in the video. Once the disc gets up to speed it mostly goes away, but if I pause on a CAV disc I can still see quite a bit of noise.

I don't remember seeing this in the past, which doesn't necessarily mean it wasn't there. Any ideas on how to solve this? I do have schematics for the player.

You probably answered your own question, bad spindle motor sound like the first thing I would look at.

I looked at my second lx-900 and it does the same thing, so it's probably a bad design.

It could be a component problem as easily as a design problem. Very likely both players used the same lot of components, & either the motor has aged badly, or (more likely in my opinion) the big capacitor used to stabilize the motor electrically is breaking down. I would investigate replacing the motor capacitor, preferably with one of the non-electrolytic large-value types now becoming more common (although a new electrolytic would probably be satisfactory, as long as its voltage rating was equal to or greater than the rating of the one it's replacing).

I have worked on a few LX-900U's and I never experienced spindle motor failures. I think their design is as good as the other manufacturers.

I've uploaded the schematics here:

http://www.eserviceinfo.com/downloadsm/ ... -900U.html

I'm able to interpret them a fair amount given my limited electronics background, but since I don't have experience working on LD players any outside input would be greatly appreciated.

Would a systematic replacement of capacitors in the power supply help lessen the video noise?

I have a strange attachment to this model player and wouldn't mind tinkering with it (or paying someone else to, but not many people are probably going to want to mess with it).

I replaced the caps after the diode that supplies the voltage to the spindle motor. My schematics show two 470uf 100v caps, while the player had one 1000uf 50v cap. There were spots on the PCB for two caps, so the single cap must have been a cost saving measure.

I installed two low ESR Nichicon 470uf 100v caps. The problem still exists, but the two caps are probably better than the one single, so I'm keeping them.