This MZ-E60 was in perfect condition - except that the battery spring had completely corroded away. Here's how I fixed it without spending a penny...
I picked up this minidisc Walkman second hand along with another player and some pre-recorded minidiscs from Gumtree for £30. It was a bargain. I sold the minidiscs on eBay for more than 3x what I payed for the lot!
The MZ-E60 (MZ-E62 is the identical European version) dates from around the year 2000. It's a well made little player (much better than the MZ-E300 that replaced it), with an aluminium front and a size not much bigger than a minidisc. It has no screen on it, but I also have the LCD remote (RM-MZ2N).
This particular one is in near perfect condition, apart from the fact that a battery has leaked in the compartment sometime over the years and the negative terminal spring has almost completely corroded away. Some bright spark had stuck tin foil down there and it made a bit of a connection - sometimes - but it was not reliably working.
You can see in the photo above the "repair" job that had been done with tin foil, and you can see what is left of the - terminal spring. The images from the service manual show what kind of spring we need to replace it - something with a wire sticking out, not one mounted to a metal plate or anything like that.
I searched for a replacement part online, with no luck. Not to be defeated, I went looking around the house for a donor...
I found an old remote control that had just the right kind of spring. A little smashing later and it's out.
The service manual gives fairly decent instructions on how to disassemble the player.
Be aware that the service manual gives you the impression that the black plastic cover (or "sheet" as it calls it - on the left in the middle image above) just lifts right off without a care in the world, but it's actually glued down to the metal casing above the battery compartment and to the top of some capacitors. You should remove this plastic cover before attempting to remove the main motor/laser mechanism. Just pry if off with a sharp knife.
To make a new battery terminal spring, I cut off the spring from the remote control that had the wire coming out of it in the right direction to match the spring on the minidisc player. I then bent it with a pair of needle-nose pliers to match the shape and dimensions of the existing spring. I also cleaned the corrosion off the casing and the + contact with some contact cleaner.
I desoldered the old spring and soldered in the new - holding it in the right position while soldering is a challenge - and put it all back together again.
Now the moment of truth... We have an led on the unit and a display on the remote. Hooray!