Recently acquired a nice TPS-L2. The device wasn't in too bad a condition. Belts were still intact, but naturally had kept their form and started to glue to the motor shaft, and pulleys. I have replaced the belts, and cleaned the motor pulley, and other components the belts utilise, and have a Walkman that now plays. I made a few mistakes, initially I hadn't realised the spring for the auto stop mechanism had unhooked itself, but have that working again now. What I am finding at the moment is that the play speed varies. First I thought the AA batteries I had may be naff, so bought fresh new batteries as the ones prior had been in a drawer for a few years. I'm still getting an inconsistent play speed though, but it's not consistent enough, or intime with the mechanism. And having put the device back together following the re-attachment of the auto stop spring, I am noting that playback will slightly slow for a while, then all of a sudden, it's like it suddenly frees up and it's back to normal playback speed. Not seeing anything interfere with the drivetrain, and the duration of the slowness doesn't match with the RPM of the mechanism. If it's left off for a while, it can also be a bit sluggish, so perhaps this could be cap related and I'll need to strip it right down to check each capacitor? I suspect this is normal, but movement can also affect the play speed sometimes, like the inertia has an affect (note: not sudden jolts, but say, rotating the device can cause a wobble). I'd love to get this in a better working condition if possible. So look forward to your help. He's a short video I took of the mechanism out of the casing before I fixed the auto-stop. I might record another to try and catch the issue which may be helpful. https://peertube.co.uk/videos/watch/f1de7cb7-51f0-4b30-b5a5-27353e06c269 (Peertube is a decentralised video host site) Having posted this originally, I have since played a cassette without the case on to see if it was any different. I note that the long the unit is playing for the, the worse it gets. And I am now wondering if the motor needs replacing. Anyway, some images of my unit. Guess that orange gunk may be some sort of grease?
The orange gunk is glue to stop the components vibrating until the leads fracture. PC power supplies used it a lot. The actual components look to be tantalum capacitors which are normally very reliable unless over-volted or connected in reverse.
I wanted to ask you if in addition to cleaning you had also lubricated the bearings because it is very likely that the lubricant used by Sony is now dry
@Silver965 that's a very good question, and the answer is: not yet. I guess that should be the next step, however, I have also noted that the wheels are corroded where the old belts were, I will try and clean them up latter but so far I haven't been able to remove what looks like surface rust in the groove of the larger wheel. Would the lubricant be administered through the shaft hole, or will I need to unscrew the 3 screws holding the shaft plate down? What would be the best lubricant?
Almost forgot, this is a video with what's happening I guess with the drivetrain. Clicking and screeching - PeerTube UK TPS-L2 Slowdown and sudden speed up - PeerTube UK Change in speed during playback - PeerTube UK Also, should RW and FF trigger autostop as well?
@AMoonRabbit This type of mechanism needs a complete relubrication, in my opinion, before any conclusion can be drawn. What I can hear in the video you posted is not what I would call a speed variation, but just a very high wow&flutter, I estimate it somewhere between 0.5%-0.7% WRMS. I made a tutorial a while ago with the lubrication procedure, it can be found here: https://stereo2go.com/forums/threads/sony-tps-l2-wm-3-restoration-tutorial-mechanical.7123/ Lubricant to be used should be watch oil or a similar very thin oil. It's also important to use as little oil as possible and also clean the parts before re-oiling. As for FF/REW, those will not trigger auto-stop. In later units, there is an auto-off feature (electronic, triggered by an optical sensor), which turns off the motor at the end of FF/REW if buttons remain pressed. However, the TPS-L2 and WM-3 do not have this feature. NOTE: Also be sure to clean the capstan and pinch roller of any oily residue, as that can cause the tape to slip, creating huge wow&flutter. Especially after lubricating that capstan bearing. NOTE2: It is also recommended to replace the entire rubber set on this particular device, including the 2 idler tires. A complete kit is available at https://www.fixyouraudio.com I assume you used a high quality belt, with uniform cutting, cause the belt itself can also cause high w&f.
@Valentin Okay, I will perform cleaning and lubrication. I need to take it apart again as I need to replace all the tape which has now become dry or just gooey. I'll buy watch oil. I bought the complete rubber set from that website, but I haven't figured out how to get the idler wheels off their shafts. It doesn't seem to be a spring clip but a complete washer holding it in place. Also the smaller guide wheel for the motor belt didn't have a washer beneath it.
Ok, in regard to the small guide wheel of the motor belt, that doesn't have a washer beneath it. At least I have not seen a washer in any of the units I have repaired, so I assume none was fitted from the factory. As for removing the complete washers, there are 2 options: 1. Cut one side of them and make them split 2. with a pair of angled tweezers pry it from beneath, while keeping your finger above. Be very careful, because if you don't hold your finger firmly, the washer can fly and you'll loose it. NOTE: beneath the big idler (FF/REW), there's another anti-friction washer. Be sure to pry just on the larger one. Also the backtension mechanism I recommend lubricating that brass part by pushing the spring down and not by removing the washer. Also note that after installing the small idler, you need to pry it upwards a bit, as you will push the shaft into the plastic retainer too much when installing the washer back. It's a detail that I have missed in the tutorial, will update that in the days to come. This step is important, because if you don't do it the idler will turn very hard, increasing the friction in the mechanism. EDIT: Cleaning the leaf switch is another a step I reccomend doing. The switch is located below small board with jacks, near the microphone. You need to take front panel out to see it.
I need a screw for just below the battery door where the battery hinge is, would any M1.4x3 screw suit? So like this? https://uk.misumi-ec.com/vona2/detail/221000348325/?HissuCode=SNZFS-M1.4X3#
Well, I went through and dismantled the unit once more. Gave the flywheels another thorough clean with finer cotton buds, replaced the two idler tyres and lubricated the points. And the unit's performance has improved quite a bit. So I am quite pleased with how it's turned out. Just waiting on the replacement screw. Thank you for your help @Valentin !
