Screws are M1.4 with a length of probably 2-3mm. You can find a set of walkmans screws here, which I recommend getting: https://fixyouraudio.com/product/walkman_screws/ The set contains both screws with countersunk head (which is what you need) and pan head. The broken plastic may be part of the molding, as some of the plastic parts are molded onto the metal chassis. Don't know for sure though, this is just a guess. Looking at the pictures I uploaded in the first post, I cannot spot this plastic part and don't remember breaking it either. Anyway, to me that part doesn't look critical at all, the walkman will work just fine without it.
The part looks like it protruded through small hole. And it looks like it might be some kind of guide for the belt. Anayway - I've played three cassettes with no hint of a problem, so all is good. Thanks for the link – I'll try the screws.
Post #20, first photo... you are not missing a screw here. This is where the external battery box attaches. You see it's right next to the 2 contacts for the external battery box.. but my RQ-SX1 does have a very small phillips screw you appear to be missing in that next photo, right on the corner radius.
Well I found me a Panasonic rq- sx72 is this worth my time to try to put a belt in it? And according to my Google search it takes two belts. But if there's any unsoldering involved it's not my cup of tea. So I'm just curious here. The battery compartment is clean which is unusual. I thought there's just one picture of it This is a very tiny unit Okay, it talked me into it. Here's one more picture Okay. Break time over.
SX72 is one of those units with rubber rings on the capstans. There are a couple of aspects: those rubber rings need to be treated in order to have good grip. Lucky from tapeheads recommended Lenor fabric softener to treat that rubber (know it sounds weird), which I have tried and it works very nice. https://www.amazon.de/-/en/Lenor-Aprilfrisch-Fabric-Softener-990/dp/B073FRRT81 Also those capstans should NEVER be cleaned with alcohol as that rubber will dissolve very easily. Apart from these, the SX units will require some lubrication and possibly enlarging holes of some shrinked gears, so definetely wouldn't treat it as just a belt repalcement unless you're ok with very high flutter. All RQ-S and SX require the PCB to be removed in order to access the mechanism. I think indeed one picture is enough as this is not a gallery showing the walkman. Also I kindly suggest to attach your pictures side by side (like this https://stereo2go.com/forums/threads/infinity-walkman-restoration.6958/) instead of one on top of each other. Attaching them on top of each other just wastes a lot of space and one has to scroll down to read all the text as the post doesn't fit onto a screen.
Hi there, I am here because recently I found my old RQ-SX72 (!) which was working, but with the "high flutter" as mentioned above. Now I managed to replace the belts and put everything back together (3 or 4 times I failed, forgetting this or that part or by just not setting this nearly invisible switch to the right position and fitting it to the mechanics). The unit works, but with some kind of music (i.e. classical) I can hear a little flutter or jitter. Not as much as before, but it is still there. I understood so far that these capstan shafts with rubber rings need some TLD, will try Lenor (I am from Germany, so my wife might have some avaiblable ). What else should I try? The mechanics looked good and moved smoothly when the unit was open. Any chance to fix it without having to remove the PCB again? Another question concerning this unit: The center gear is held down by a very small conic spring, did someone manage to find a replacement for that? I bought a 2nd RQ-SX recently and there this spring flew away. Thanks and best regards, Stefan B.
First, do some treating with Lenor. Check the pinch rollers also, on these units it's very important to be in good condition and clean. Rollers can be cleaned with IPA, just be careful to not touch the capstans while doing so. If mechanics moved smoothly without significant resistance, it's probably fine to leave it as-is. Although I would recommend lubrication. As far as the conical spring goes, searched for that myself in the past and was unable to find one. The solution is to find a cheap donor. But generally speaking I won't expect these AR10 to perform as good as AR90 mechanisms in terms of W&F. The AR10 has gears connected directly to the flywheels, so teeth engagement (which can be heard on these units) will create some flutter. On AR90 the geartrain is driven by a separate pulley, so it's isolated from the rest of the mechanism via the rubber belt.
It is the mechanism type. I have added it for quite some models on Walkman.land, we just haven’t made it visible to visitors yet. All these have AR90: RQ-S50, S60, S70, S75, S80, S90. More to follow.
AR90 is the mechanism used in RQ-S series, while AR10 is specific to RQ-SX series. But it's to be noted there are a couple of exceptions, like SX units with AR90 mechanisms. There are different generations also, like AR90 has the early pad lifter carriages with known problem of pad lifter and roller holding pins bending. Attached pictures for reference.
Hi, thank you very much for the explanation and pics! I used the Lenor trick yesterday, but it did not change anything. Could the flutter come from bad pinch rollers as well? I cleaned them with Iso-Propanol, but maybe they are hardened and tend to slip? Are new ones available? Thanks Stefan B.
Out of curiosity, what W&F figure do you get on this unit ? Have you measured it ? Given you say it's audible only with classical, I would expect it to be <0.30% WRMS. New roller are available, but only the rubber. And I don't recommend replacing them (unless they're really bad condition), as chances are the new assembly will become eccentric. How much was the unit used ? Is there a difference between FWD and REV ?
Well, if I knew how to measure W&F, I would be pleased to do it Slow pop music also shows significant W&F. The unit was used regularly 2 or 3 times a week, back in 2000-2001. Since then, it was stored in the basement, until I recovered it recently. Will check FWD/REV differences when I am home today in the evening.
Question was if it was used now, after repairing it. Fact it was used in 2001 is irrelevant now. Main point is I would use it for some time before drawing conclusions. For measuring W&F you need a test tape, like this https://fixyouraudio.com/product/speed-calibration-tape/ and WFGUI software: http://www.ant-audio.co.uk/index.php?cat=post&qry=library (first link here). I also suggest (since this discussion is becoming long and unrelated to the original topic) to start a new one (with suggestive title such as "RQ-SX high W&F") in the tech talk section. This way it will be more visible also.
