Anyone know how to access Capacitors on a Walkman WM-3?

Thank you for the enlightenment on the issue! As expected, it seems that both our walkmans have identical electronical issue(s). I bridged Q603 and the motor now runs.

To be honest, I'm almost totally blind when it comes to how these electronics stuff works. I've repaired many units, but mostly it was just problem with the mechanics and simpler electronic stuff.

I read the schematics when I got stuck with this issue, and I only went as far as suspecting that something wrong with the servo. I didn't really know what to do about that, that's why I just tried replacing the entire servo board as I got a parts unit (sadly, minus the motor). When that didn't solve it I turned my eye to the motor, but since I wasn't sure that's the problem, I did not dare open it up too much. All I did was change both FG wires, but that made no difference.

Thanks to your guide, I got the courage to open it uo, and found what seems the be the problem! Apparently, the internal connection to the FG coil has rusted away, so all I did back then was rewire FG terminals that werent connected to the coil. It's kinda late here, so I think I'll just try connecting them tomorrow.

Now I wish I didn't pass up on an ad for 2 used MNF-1600B motors last month...

 

I'm soo happy to finally have a solution. The thing is I didn't expect there would be a problem with circuit board electronics too, because the most common repair answers I saw was either a bad belt, bad capacitors, or broken Motor. But then I thought that the motor shouldn't be able to spin at all for those 8 seconds if it was broken and I tried so many Google Searches trying to find someone with a similar problem and nothing turned up. I think that's why it's been so hard to diagnose because the servo amp board isn't a area people usually look at.

I was scared too to touch that area. Because of that fear of damaging it more than I already have and how rare replacement parts is. At first I thought the motor wouldn't keep spinning because I .Broke off the DC supply jumper wires and did a bad job of soldering it back onto the board but then you said you had a similar problem which prompt me to keep on reading and researching what each component does and how it works.

I only wish I can re title the thread to Motor Stopping problems so others like us who Google the problem find it easily.



If you open up the motor and repair the FG connection can you post the results and how you did it I've unscrewed the motor but have been too scared to actually open it in case I put it out of action for good.

 

I can only remove the metal case the motor is put in its impossible to get to the coils it's too tight

 

Anyone have any ideas on how to get into this I would use pliers but I'm scared I'm gonna rip off the wires.

 

You do need a grippier tools than just tweezers to access the FG coil. Even my small pliers are to big, so I used my scissors instead. The FG coil is attached to the bottom of the plastic piece which houses the brushes. That plastic piece is a friction fit piece with 4 latches that stops it from going too far in. It's pretty hard to use pliers, as the top of the latches are slanted, so you wouldn't get much grip. With scissors, you can get a grip by slipping it in the groove between the plastic and metal. Then you can carefully wiggle the whole thing out (there's probably a safer way to do this, but that worked okay for me).

I guess damaging the wires is a concern, but you can always re-solder them. Admittedly, that is a pain since it's so small, but since I did replace them already I didn't mind doing it again. I'm much more concerned abour resoldering the FG coil itself. In my case, the connection have actually rusted through, and the coil was left inside the motor when the plastic piece was removed. I'm not sure my soldering skills are up the the job for something this tiny.

Am I right in assuming that the coil is just a wire loop? I'm guessing the one cable is soldered to the outer end of the loop and the other is the inner end? If that's the case, how am I supposed to solder the inner end? I can see the outer end of the wire, and despite being so small, I can at least try. The inner end has broken clean off though... Can I just solder it anywhere along the loop?

Here are some pics, pardon the poor lighting and perhaps my not too good soldering skills... (note that one of the wires have broken off)


The whole assembly


What I pulled out at first


The separated coil. The 2 plastic pins lines up with holes to align the oil and there are notches where the wire connections are made.

 

I actually made a thread about this problem before, but did not find a solution. I'll just link this thread there.

 

I know this is a bit of a dick move reviving an old thread(ugh this was a typo earlier and said friend verbal diahorrea soup) but I never got a chance to respond since I've been inactive for a year. Did you manage to fix the coils?

Also I have a bit of a problemo I've lost a few screws to close the Walkman in its enclosure D: anyway to get a replacement screws?

 

In this case, no. Well, it may perhaps be fixable with a lot more work, especially since I have a learned a lot since, but I had a spare back then, so I just decided to replace the entire motor. The corrosion was too close to the loop, and there weren't any loose end to solder to, anymore.

As for screws, I used generic screws sold for cheap Chinese mobile phones. I buy them in bulk and they fit a lot of stuff, including the case of the WM-3. You need a bit longer ones of there black plastic piece on the sides.

 

You fixed it God I'm jelly. Can you link me screws on Amazon or something that would do the job as I cant trust myself to find the right one.

Also how easy is it to come by another motor on Ebay? Or if you could can you give me a fixing the motor coil guide for dummies?

 

Eurgh another headache I've lost the grey plastic volume sliders that fits onto the black circuit board one. Is it possible to get another one. Or maybe get another one 3d Printed from someone?

 

Finding another motor by itself may be very difficult, It'll bee much easier to find a donor unit to cannibalize. I don't suggest a walkman though, other series using the same motor are all quite expensive stuff. Try to look at the older sony business recorders/micr0-cassette recorders. Iirc, these are among the units that use the same type of motor: TCM-100/TCM-600/M-101/M-201.
I didn't actually fixed my coil, but it's supposed to be simple fixed. Just that the wires have been severed by rust.

There are 4 wires going to the motor, 2 are for powering it. The other 2 is for the FG coil. The coil itself is basically just a very long loop of thin copper wire wound to form a ring.

The screws are something like this (this one's kinda expensive though) https://www.ebay.com/itm/10pcs-Cell...157190?hash=item1ccfd88286:g:isUAAOSwjL5ZJa-Y. Sony specified in the manual 1.4 x 4 screws

 

Thanks I might resort to spare parts later if I'm going to throw away the motor I might as well die trying to resolder the wire to the wire loops assuming I have tbe same problem. Coils are just essentially wound wires to make electromagnetic waves. Maybe itll be possible for me to note the number of times its wounded round unravel it solder the connection then wound it round again?

 

An update 2 years later. I found someone selling a WMF-1600B motor standalone on eBay the other day which I bought, so I decided to have another go at opening the non working motor consequences be damned and the most bizarre thing happened

When I opened it up to reveal the solder points of the wires there were 2 in opposite notches like you said I randomly decided to put the coil back into the motor and press play just to see if me somehow giving it some air would do anything and it randomly decided to start playing again without stopping after 5 seconds , operation light glowing and everything. I havent screwed it back in because I'm worried about not knowing the how and feel like I've fluked it.

So I took the coil out and the plastic thing with notches (they're still attached as one thing) and then rearranged the plastic cover thing that fits between the notches, and when I put the whole thing back in it wouldnt play again? Depending on the position I twist it itll either work normally or stop? Does that mean somethings loose inside?

The coil connections on mine havent rusted through though the plastic and coil still look very clean. I honestly think it might have something to just do with the wires having been loose. So I'll just use isopropyl and reflow the solder. You're right about the coil wire being so thin though at first I honestly couldnt see what you were talking about until I looked at mine and saw that 2 strands of wire from the coil extends down either end to meet the wires that come from the PCB at the solder joint. I think you might have to use a magnifying glass or one of those eye pieces or something with some tweezers and tape to secure it while soldering

If I somehow manage to get my current motor to work I'll be happy to sell on the WMF-1600B i got from eBay to you or someone else who needs it on here for the same price I brought it for

Whenever I look inside a Walkman and see very small parts and wires I think to myself how the f$#% did Sony manage to assemble millions of these together


Eww I can see my fingerprints

 

I think I've figured out the problem



One of the strands of wire that conjoins the redt of the coil to the solder joint was severed in half somehow. You can see it above. Me twisting the thing a majig while it was in the motor casing probably made the 2 touch here and there so it would work

Also I was confused at first because every motor I looked at on the internet used Carbon Brushes because the logistics of big carbon brushes fitting into this tiny motor doesnt make sense but apparently this motor doessn't use Carbon Brushes it uses 2 copper contacts that touches the commutator. When I used isopropyl to clean the contacts inside there was a lot of dirt and black residue not sure if it was rust so that might also have contributed to the problem



I used tweezers to push the broken strand of wire together. I'm too scared to solder them together today because I feel like I'll melt the plastic but I'll do it tomorrow then reattach the wires.

 

Excellent. Not being rusty means there's still something to work with

Talking about spare motors, you can actually get the same motor from lesser & much cheaper units. I think the Sony M-201 micro-cassette recorder uses is one of them.

 

I've been looking everywhere for someone else with the same issue for years. I tried so many Google Searches trying to find someone with a similar problem and nothing turned up. My TPS-L2 was lying forgotten in a drawer because I thougth it was a problem with the servo amp board.
Thanks to your guide, I found the problem. One of the wires of the FG coil was severed in half. I opened up the motor and repaired the FG connection, and my walkman is working properly.
Thank you very much.