Hi After removing a melted rubber band of this WM-501 I noticed the pulley was stuck, I got it rotating with some encouragement by pushing with finger. I have some questions re lubrication - - Is it possible to lubricate with it in place, without removing the little washer on top? - If not, how best to remove tiny plastic washer on top without bending/breaking it? - is Moebius 8000 watch oil an appropriate lubrication for this pulley shaft?
It is, but it's not going to last because you won't remove the belt residue/old grease, just mix it with oil enough to drop its viscosity. Something I do NOT recommend. There is more than one way to remove it. Bending it isn't a problem (you can bend it back after removing) and breaking it is highly unlikely. The real concern is making sure it doesn't fly away while removing it. There are replacements available from FixYourAudio, so even in a worst case scenario you shouldn't worry about it too much. Next, I will list 3 methods: 1. Use a pair of tweezers while keeping the other side with your fingernail. Put the tweezers under one side of the cut and lift the washer. After half of it is lifted, firmly grip it with the tweezers and remove it completely. This is the method that I use but don't recommend as it requires quite a bit of experience, otherwise chances are that washer will fly and you won't find it. 2. Stick a small piece of scotch tape over the washer and proceed similarly to what's described at point 1. This way, you eliminate the chance of the washer flying away. 3. Use a tool similar to a cuticle cutter (see picture attached). More than appropriate. Any watch oil will work just fine for these walkman mechanisms. The only thing that is important is to use oil not grease and to use a thin oil.
Thanks managed to get it off. I appreciate the tips @Valentin, I used some thin selotape, and put one facing upwards under the split washer and then another piece of selotape over the top like a sandwhich, and then placed the needle nose pliers to pinch tightly where the tape was so as not to damage the split washer, a little wiggle and pull and it came off no problem. I had to place a tiny flat screwdriver under the pulley to lever it off the post - and I'm concerned that having done that, the post has a slight wiggle now, is it expected to have slight movement, or should it not budge at all? I wonder if a watch repair tool like this might help so that no uneven pressure is applied on the post whilst removing pulley? There was some green residue in the center of the pulley probably migrating battery acid related, I've cleaned initially with isopropyl, is it worth trying to use some very fine sandpaper inside the pulley hole? I'm resisting scratching too much with anything metal, as I assume these are brass and I don't want to create any more damage on the surface that moves around that post. It seems the manual only notes 3 parts (149,150 & 151), however mine has 4 - the pulley, one nylon washer (1), one metal washer (3) and the split washer (plastic) (4)!
The shaft itself has a slight wiggle ? That should be solid, shouldn't have any play. I can see a small bump on the metal plate it's fitted to, sign that it has been pulled up a bit. If the play is small enough to not cause increased friction, I'd say just ignore it. Otherwise you can remove that battery cover and put a small drop of glue on the back of the shaft.
Yes the post has tiny wiggle, barely noticeable - but I'm fussy lol. I pulled at the pully a fair amount before resorting to leveraging with tiny screwdriver, so that may have slightly pulled up the metal plate the post is attached to. I managed to get the section out to inspect it in detail: Sounds reasonable re bit of glue on the bottom, or maybe even resolder perhaps - unless that would block the battery sliding in? Although now I've put oil around the base of that post which I think has seeped right through underneath, so if I wanted to glue anything underneath I'd have to thoroughly remove oil, is Isopropyl any good for that or would I need a stronger degreaser of some kind to make sure any glue works as best it can? There is actually a Japanese guy talking about what seems to be a similar issue with the same pulley on a WM-501 here: but it's hard to figure out the discussion even with translation.
Initially I wanted to suggest soldering and I think that can also work. You will need to sand the surface or scratch it well with tweezers for the solder to stick. And as you said already you need a very thin solder blob, otherwise the battery might not fit anymore. You can file the solder after to make sure the battery will fit. Yes, IPA is enough to clean any oil that has seeped through. The Japanese guy, have seen many of his videos but due to speaking in Japanese I don't quite understand what he's talking about. The main idea, as stated before, is to make sure that pulley can rotate freely without resistance. If it can rotate freely, the you're ok.
