Hello, I am trying to fix my old WM EX-50. It had an old battery that corroded a bit around, but I cleaned all, disassembled the nearest capstan and cleaned / lubed / greased. The belt was also completely soft and left pieces around. I got a new belt. I also opened the motor to clean and lube. When I reassembled, initially I was worried that nothing was working even with a new battery. Then I found the switch that is activated by pressing the buttons. So I could leave the board flipped upside to see the mechanism and test with the motor running. It was looking all quite ok, maybe except the reverse button which was not working reliably, but it could be that the belt was a bit greasy because I might not have cleaned all well after lubricating. Then, a strange thing happened: the motor stopped running even if I was keeping the switch pressed. Then working again for a while. Then sometimes when pressing the switch I got only a bit of movement and a small click sound. Then working again, then nothing. I thought that the motor flex cable might be damaged, but it looks good and testing the continuity of contacts all seems ok, it is not so easy to test though. The motor rotates smoothly and with even speed, when it can be started. Can it be there is something wrong in the power supply or motor servo controller? How do you suggest to proceed? Thanks for any advice Marco
Models with this mechanism are known for leaky electrolytic capacitors and this one is no exception. There are at least 2 electrolytics in the servo circuit from what I can see, so if you have not reacapped the walkman, this is the first thing to do even if they may seem fine visually.
Thanks for the hint. I have no experience soldering smd components and have only a basic soldering iron, I am not sure if I should start this job without testing my skills, so I will try to do some trial soldering before working on the WM board. Or maybe try to get access to a soldering station.
If you intend to learn to solder and think a soldering station will be useful in the future in other projects, I think getting one is a good idea. You can start with something cheap or get something more decent like a Weller WE1010 for example.
Hello friends, I am still pondering how to replace the motor drive capacitors with my limited equipment and skills. I have a very basic 15w soldering iron with a too large tip, but I can buy a thinner tip or sharpen my tip. I also have a hot air gun with digital temp setting that should reach 300-350°C. However, I fear that I will melt surrounding components such as the volume wheel or red LED light. Accessing the cap pins, especially for the cap near the volume wheel, seems quite challenging. Is it possible to use something like a needle or steel wire connected to the soldering iron to heat the cap pins? I guess it will be hard to reach sufficient temperature in this way. Maybe I am over concerned but I do not want to do damage. Do you have any recommendations?
Wouldn't be too concerned about removing them (as the caps can be cut above the plastic plate), but more about soldering the new ones in. My recommendation would be a smaller tip, which in this case means a different iron or a soldering station. The LED is easy to remove, but the pot requires a bit more work. If you're confident you can remove both without any damage (to the parts and pads), remove those first.
Hi Valentin, thanks a lot for the advice and for the great video! Now I know what to do. I think I can remove both LED and pot, then I may try with the hot air or other method. I will get a better soldering iron in any case, it makes sense.
Hello, I procured a proper soldering station and could remove the two caps close to the motor servo IC. One opened up when pulling it, the other is still ok. Now, I have further questions for you: -I only have a basic electric tester (see picture) which as far as I know has no specific mode to test capacitors. I wanted to check the cap that I desoldered, is there a way to test it without a specific capacitor tester? -Without a way to test for good or bad capacitors, shall I in any case desolder and replace all electrolytic capacitors on the board? I am lazy If so, where do you recommend to buy new caps? I am in Austria. Thanks for your support, this repair is much more work than I thought but it is quite good for learning.
Given these models are known for having problems with capacitors, think it's a good idea to replace all capacitors including the 2 x 22uF@4V sitting on one side. Caps you can buy at any electronics parts distributors, but being in Austria I would try TME first since shipping will be cheaper. If you want easy soldering, I also recommend going for SMD tantalums instead of the electrolytics, in the smallest footprint you can find at TME (for most smaller ones it will be 1206). The 330uF@2V you're likely to only find in tantalum version and with 4V rating, but the 4V tantalums are smaller than the original 2V so this won't be a problem.
Hello, I am sorry to bother again but may I ask if the list of capacitors to be replaced is correct? I think my list should include all the cylindrical electrolitics, plus the two 22uF@4V that are squared and mounted on one side. I just want to be sure before I go and order them:
Looking at the board you have: - 330uF (3pcs) - 22uF (3pcs - 1 round + 2 flat) - 4.7uF (3pcs) - 2.2uF (2pcs) - 1uF (1pcs) If you go for SMD tantalums instead of electrolytics, you can replace all 3 x 22uF with same tantalum. Go for the smallest you can find, 1206 package if tantalums.
Wow, it looks like TME has minimum order quantities of 500 or more pieces. I tried Farnell Austria, but I also get direct ship charges of 25€ and handling charges of 15€ so I have to pay 70€ overall...I do not want to spend that much, do you know any alternatives?
