Howdy! It's been a while since my last restoration attempt. Today is my first time restoring a Walkman composed primarily of smd capacitors. The good news: besides the 470uf caps I have everything else salvaged from other stuff I had laying around The bad news: none of the buttons in this machine work besides fast forward. Since I only have a standard soldering iron, my technique consists of soldering one leg of at a time of the capacitor. (I only ripped 2 pads off this time ) Before removing caps All caps removed Seeing the PCB through a jewelry lens magnifier, I can see some damage. Oh well, I'm certain baking soda and water will deal with this. There is also some green corrosion on the play button legs, this might be why I couldn't get it to play. Is it possible to substitute the 2 470uf capacitors required with a higher or lower microfarad value? Also does anyone have tips on how to jump traces? Ive never touched smd beforehand.
Don't reuse caps from other machines, chances are they are equally as bad. Buy new caps and do it properly. Jump broken traces with thin wire wrapping wire (26/30 awg)/extra capacitor legs. Clean board with isopropyl alcohol to get rid of flux residue. For buttons, check for continuity, replace or rebuild tact switches if deoxit/ contact cleaner does not help. For 470 uf, get UMW0G471MDD, and adapt to smd by folding the legs and trimming. See: http://www.stereo2go.com/forums/threads/list-of-common-walkman-capacitors-2017.1246/
I found new nichicon capacitors that fit (although they are all through-hole). I am following this procedure where i can to convert my caps to fit. Also I found out that the 470uF caps serves the same purpose as used in the Aiwa hs-pc202, it's for smoothing and part of the current regulator for the external battery gondola. I'll buy a multi-meter and a tact switch today.
Converting through hole to SMD (and vice versa) is something I do often. The external battery cap replacement is optional. The tact switch might not be readily available in this size and configuration.
I couldn't find a tact switch, to fit. I'll check with the multimeter if the switch still has any continuity, if not Ill see if I can break the 4 plastic pegs holding in place the metal cover. If that doesnt work Ill attempt substituting it with a tact switch salvaged from a dead discman.
To clean the old tact switch, disassemble it and polish the contacts with a fibreglass pen, and coat with deoxit.
ALright the switch replacement is half a millimeter too big.... I'll try a shorter one soon. To identify and troubleshoot why a function isnt working you need trace the signal back to the ic or something, but how do you trace it back to the source if they're is a an open connection in the circuit? I know im supposed to clean, re-tin capacitor pads, flux and solder new caps. But then I need to use the tracing side? For tracing components how do you go about doing that exactly? (sorry for the noob question)
Use the service manual if available. If not, use a microscope/magnifying glass and trace manually. Bridge any corroded (blackened) traces by scraping off the coating just after and before, and solder a strand of copper/wire across. For corroded vias (holes that go the other side) I drill out the hole with a pin vise and use a wire strand to bridge. These are the more common broken traces you'll find in a badly corroded board.
I've been working on this on and off in my free time after work. I've attached all capacitors and traced a couple places which failed a continuity test. Seeing as how the original button had signs of corrosion even though it still works I replaced it with one found from a broken wireless mouse. I accidentally broke the FF/RW slide switch, so i replaced it with one similar found from a cheap late 90's Aiwa. The mechanism works wonders, a stretched belt i replaced from a panasonic rq-s60 fits nicely in the machine. Yet the play function still doesn't work. Ill try to jump the wires like this and see if it makes a difference: I need to look at the service manual and try to understand where the play signal comes from, it might be that the signal isn't even reaching the play button. I'm unsure as of how to fix this, any suggestions/advice would be greatly appreciated
Here's an update. after re-soldering the pcb to the walkman. I was surprised to find life. now it's another issue though, when i bridge the contacts close the lever then the rewind function works. Play works sorta, for a couple seconds then the gear cam does one of it's half rotations then everything turns off.... Im also getting noise out of my headphones, it's not music, nor does it last any longer then 2-3 seconds but it's progress.
If you look at the schematic, Play/Stop is S9 and S10, top right hand side. They are connected to the hold switch S7, which may need replacement. Also check S8. To test if the switch is at fault, short E1 of transistor Q11 to ground (-). REW/FF is completely separate to logic in this model. For brand new replacement switches, buy one of these generic ones, which I stock for walkmans. File down the actuator to match the old one. To find out which one of these fits yours, you'll need to measure the size of the original and compare it to one of them in the datasheet. EG1315AA PCM12SMTR MA12R SSSS811101 SSSS811501
This looks very similar to my HS-PX310 which I'm trying to repair. I have the same issues and I have found the non working play button to be a very common issue - mine went wrong after about 2 years when I had it from new. My suspicion is the electromagnetic actuator - maybe it becomes permanently magnetised? I have x4 310's, so far I have wrecked 2 trying to fix them - they are technically very challenging. I'm hoping the last two survive!
Just watched your video - it is an identical movement to mine - in fact I've been using your circuit diagram to help me - it's abo 90% the same. My first machine is really playing up - buttons now don't work and continuously auto-reverses. I'm sure some of the issues we are having are the same. I've ordered some new testing equipment so will let you know what resistance my working solenoid is soon...
On the very similar machines I have I’ve found the play button issue to be the small track link on the rear of the PCB where the solenoid is soldered in - see my thread. You can test the solenoid by clicking it to closed and then touching the terminals with wires connected to the battery.
So i tried what you said. The good news is that the solenoid does work, although like your model it also makes mine auto-reverse to infinity, or requires me to hold down the play button.
I’ve dealt with this about 10 times in the last few days but I can’t remember exactly what causes it. I think it’s mechanical - the white plastic lever which rests on the right hand plastic cog - sorry poor description! Try manually actuating the solenoid without power, then manually turn the right hand cog to play position, them do the same again to stop - think this should put things in the right place...maybe. The above assumes the circuit board is detached and flipped over away from you.
