I reconnected my HD CD-1 a couple weeks ago, as a transport, after maybe 2 years and it plays fine, but a couple days ago I noticed a scratching sound, so I took the cover off (a lot like a chinese puzzle). Directly on top, there’s a metal disc connected to the spindle over a metal plate/shield. This disc is coming into contact with the metal plate but should be ~ 1mm above the metal plate directly below it, but it scrapes on the plate. Probably deeper down it’s now off center, which would likely require a new mechanism
THE GOOD: After applying a little WD-40 under the outer edge I put it back in my system sans cover. I am very, very, shockingly impressed with how much better it sounds without the cover,