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Soy PS1350

Posted: 10 Nov 2018 17:50
by Geoff013
I'm trying to fix an old PS1350 for a friend and would appreciate some guidance, please.
After getting the turntable working (alignment of the start micro switch), I fitted the drivebelt and lowered the platter on the sprindle only to notice the platter is firmly touching the frame of the turntable thus stopping it rotating.
Although I can install a plastic washer to increase the height of the platter, however the service manual doesn't show such a washer and I'm wondering if I should be making other adjustments to raise the platter.

I would therefore appreciate any advice, please.

Re: Soy PS1350

Posted: 11 Nov 2018 22:34
by paul401
Hi Geoff,

this seems to be a common problem on some Sony decks from this period, 1350, 2350, 1700 and others, but these have all featured in previous threads with this issue. The problem is the thrust plate at the base of the spindle shaft seems to disintegrate with age causing the spindle (and hence the platter) to sit too low, causing it to catch on the plinth.

The platter is a friction fit on the spindle, being slightly tapered, so adding washers here would stop the platter being a good fit on the spindle. Also the cog that is fitted to the spindle also has a small nub which engages with and starts the auto return mechanism, so the height is quite critical. The height that the spindle should sit in the bearing shaft can be gauged from the recess cut into the spindle, where the retaining screw fits (images 1.6 and 1.7). in the service manual.

The solution (or solutions) that have been suggested are either delrin (or nylon) rod or washers placed in to the shaft to act as the thrust plate. I had a 1700 model and the end of the spindle was a half round shape, which formed the bearing, the thrust plate in which it sat was a dished shape piece of metal (which itself sat on a hard fibre(?) washer, couldn't be sure as it was the metal part that had worn away, I took a photo but the metal broke up as I cleaned it.
I think the bearing design may have changed during production times/models so take a look.

It is possible to raise the whole shaft, using the locking nut where it fits the plinth, but obviously this won't help if it's the actual bearing that's defective.


Here are some pics I took of the 1700 ( the old thread may still be on here somewhere)

pre cleaning

after cleaning

end of spindle/bearing + washer

end of bearing assembly

Re: Soy PS1350

Posted: 12 Nov 2018 15:03
by Geoff013
Hi paul,
Many thanks for you detailed response and pictures. Now I understand what's required, I'm sure I can find a suitable washer.
Best regards

Re: Soy PS1350

Posted: 12 Nov 2018 22:23
by paul401
glad the info/pics where of some help, there is no detailed info on the make up of the bearing in the service manual and no one ever quite knew what should be 'down there' so to speak :-k
My before and after pics are not great but highlight that my slightly over zealous cleaning 'did' for whatever parts/remains where at the base of the shaft!

I think a flat surface may be the ideal for the ball end to rest on, but one chap did use washers and all seemed to work ok. Not sure how long they last, but it's a cheap fix and easy replacement as and when they do. Also you can add as many as required to get the correct height.
The thrust plate being softer than the end of the spindle avoids any risk of damage to that, which would be harder to sort out.

Let us know how it goes


Re: Soy PS1350

Posted: 15 Nov 2018 12:32
by Geoff013
Hi Paul, Thanks once again for your email. I've had a look at the orange fiber washer and although it shows some wear, it still looks OK. Unfortunately the platter is still touching the base at odd points around its travel which may be due to this fiber washer being too compressed. However I've now fitted a small rubber "O" ring at the top of the saft just under the toothed wheel which also fits nicely in the recess of the brass housing and raises the whole bearing but approx. 1.5mm and works great - no noise.
Bear regards.

Re: Soy PS1350

Posted: 15 Nov 2018 23:08
by jcave
Hey Geoff do you have a picture of the "O" ring or where I could get one? I'm still not able to get this thing right and it's driving me nuts. Thanks, jeff

Re: Soy PS1350

Posted: 17 Nov 2018 00:05
by paul401
Hi guys,
I think Geoff you may have come up with a different / additional answer / idea to this issue, which is interesting.
I'm a bit concerned my pics ( and / or comments) may have been a little misleading - not intentionally! Just to clarify the 'pre cleaning' pic shows the dished metal plate at the base of the shaft (as best the pic shows) which I assumed was the thrust plate, the second pic 'after cleaning' shows the 'fibre' washer and black 'nub' in the centre - the metal plate had vanished (disintegrated?) with the cleaning.

Looking at the pics afresh I now wonder if the metal plate was not in fact the thrust plate - or at least not as I had first assumed. The last pic shows the base of the shaft from the underside of the deck, you can see the fibre washer, a centred black plastic piece and there is also a 'c' clip, which fits into a groove cut into the inside of the shaft, the whole thing is set/sealed with hot melt glue.
With further cleaning and disassembly the black plastic part also broke up into pieces! It's a pity that the pic is blurred at that point #-o . Geoff was the black piece intact on your bearing?

The pic with the bearing (spindle) end taken together with the fibre washer may have caused the confusion, although the spindle end fits in the washer, I don't believe this is how it works - sorry should have taken separate pics to avoid confusion. In my defence I think I too, was at the time, trying to figure out how it should all go together - from iffy pics and missing parts :-k

So, looking again, I'm now wondering if the black plastic part extended through not only the fibre washer but also the metal disc (washer)? I originally thought the dark centre spot was just the 'dished' shape, but now I'm thinking it might be black plastic - though it looks as though there is some curvature on the metal disc - so the plastic 'nub' sits in the dished part perhaps? Does the bearing end of the spindle sit on the inner curved edge of the metal plate or on the plastic? I'm thinking not the plastic.

@ Geoff, it was at the base of the shaft that nylon washers where added to replace the 'lost' metal plate/dish - and thus regain the lost height of spindle/platter. I'm curious about the 'o' ring, does the nylon toothed cog sit on it, I'm thinking this would cause drag - or have I got the wrong end of the stick? :)

@Jeff, if it's still scrapping then an additional washer would raise it up, there is a little bit of lee-way in regard the trip mechanism alignment. The platter only clears the plinth by 2mm. on these decks.

Again sorry if my initial thoughts where incorrect or misleading and if I've further muddied the waters with 'new thinking' on this. I doesn't help that I'm I the process of moving and everything ( inc. Sony deck) is packed away, so I'm working from fuzzy memory and fuzzy pics!! :?

However, I'm sure we can reach a working solution.


Re: Soy PS1350

Posted: 24 Nov 2018 19:14
by Geoff013
Hi paul, Unfortunately I've given the deck back to my friend so I'm unable to show any pictures. I didn't see any black washer when I removed the spindle and just thought the spindle rested on the red fiber washer on the bottom of the shaft housing. However, whist searching for a suitable solution to my problem I found this pack of different size rubber "O" rings that I'd purchased for another project and found one that was good fit and tried it - nothing scientific. As for drag, I assume as the cross section of the "O" ring is round there is little surface area touching the underside of the white cog and thus delivering little drag.
Hope this helps.