nakamichi mb-2 disc loading problem

[deafdumband50]

Hi. I'm new to this.
I have an early 90's Nakamichi MB-2 multi-disc cd player. When I load a cd it goes in fine but when I press play the drawer just opens back up and slides back out. I don't think it spins at all during that time. I'd appreciate any help I can get to fix this. thanks

[stephensank]

If we are talking about an MB-2, and not an MB-2s, the first thing to check is whether or not the second stage of loading is happening fully. To check, you need to remove the top cover & observe what happens when you load a disc. Whether you hit play or not, once the drawer is closed fully, the second step is for the laser/transport mech to be lifted up under the cd until the cd is clamped & free to spin. If you aren't sure, just turn off power as soon as the mech stops doing anything & try spinning the cd with your finger. Should spin free & level, securely clamped by the magnetic clamper on top of it to the platter of the transport mech.
If this checks out, power up again, load a disc & see if, after cd is clamped, the disc spins within five seconds or so of clamping. If not, try re-loading & see if it starts spinning once you give it a clockwise spin with your finger. If yes, the platter motor needs work or replacement. If not, you may have a fairly rare case of a bad Sony KSS-210A laser.

[deafdumband50]

very helpful info. Thanks a lot! I do have a Japan made MB-2, not the MB-2s. I also failed to mention that the unit was taken in for repair for the same problem years ago. They replaced a small part but I can't remember what it was. If it was the laser then I'm wondering if the laser is good and the connection is bad. I think you sent me on the right track though. I just have to figure out what to remove to access the laser and it's wires.

[stephensank]

Usually the only thing the MB-1/2/3, aka CDPlayer1/2/3, need is belts, primarily the main loading belt, i.e., tray belt. You can greatly extend the life of that tray belt by reducing the tension of the roller-ended leaf spring that catches the tray at the very back end of the tray guide rail. This spring roller holds the tray fully closed to counter some play in the drive mech, and the tension is excessive, causing premature belt slip. There are two other belts, both of which require removal of the entire mech from the unt to access. One drives the laser/transport up & down, and the other moves the changer trays unit up & down.

[deafdumband50]

Great - I'll look at the belts too. It might take a while because a friend has the unit and he's out of town for a week, but we'll work on it. Thanks.