Nakamichi MB-1s haunted tray

[mikehd]

I have a new to me MB-1s that has an odd tray behavior. It will somewhat randomly close immediately after opening, sometimes after a few seconds or longer. I do have the service manual but after a review nothing jumped out as being responsible for this. Maybe the load/unload switch is the problem?

 

[Lampie519]

Switch.
Possibly dirty.

 

[mikehd]

So not the tactile load/unload switch but a tray fully open switch?

 

[Lampie519]

Yes. This one could be greasy or just dirty.
It acts now like you are pushing the tray and it will close.

It may not look exactly like the photo i sent but i guess something similar.

 

[mikehd]

Thank you for the clarification. I have the service manual and couldn't identify any switch that looked exactly like that, but have found what may be the equivalent. Look at 19 in the assembly schematic.

 

[tomchr]

Yep. That's the one. You can often get it back to working order by cleaning the switch. An isopropyl alcohol wipe or touch with a mild abrasive like a pencil eraser will often do the trick.

Tom

 

[mikehd]

I guess my next question is whether it will be accessible without dismantling the tray mech. I'll open and see.

 

[Lampie519]

I think it is accassible if there is space enough on the side of it.

 

[mikehd]

Here's the switch. Looks to be soldered in place. I think my best hope is to spray some electronics cleaner into the area around the white plastic lever's pivot point.
Oddly enough, the behavior has been better since I put the cover back on and placed it back in the shelf.