TP90 tonearm repair

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fredchong
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TP90 tonearm repair

Post by fredchong » 23 May 2019 10:28

hi friends of Thorens ,

I received a TD160S MkV that had a TP90 with a cracked VTA plastic bracket (see picture of the part with arrow pointing that I want to change) . I have bought a part to replace it but not sure how to remove the square block (that holds the tonearm rod) from the rotating barrel . This needs to come off before I can remove the plastic bracket. Any one have done this before or have any ideas ?

I have managed to remove the whole arm from the turntable . Just left this last step to solve before I can replace the bracket. I can also remove the rod from the square block. That is not a problem.

Thanks for any help ,

Fredc
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StephDale
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Location: Bristol, UK

Re: TP90 tonearm repair

Post by StephDale » 09 Jun 2019 13:14

Fredc,

Have you solved your problem yet? I've just rewired the TP90 on my TD2001, so have managed to get it apart. Leave the arm tube ('rod') in the yoke ('square block') as adjusting the top bearings is tricky to do and be sure your arm will still work as well as it can.

I will just mention that the cueing platform you have arrowed is made from a very good grade of styrene so can be glued with liquid styrene cement as used for plastic model kits. I have repaired a couple like that:
1. Remove the two screws and washers that are holding the cuing platform to the stem.
2. Flex the cueing platform to open the crack and apply a few drops of liquid styrene cement to the crack using a 00 brush.
3. Allow the gap to close, which will probably leave a little cement on the surface.
4. Leave to dry off for a day or two.
5. Re-fit the screws and washers - don't over-tighten them or you'll have to do it all again!

If that doesn't work and/or you still need to get the arm apart then drop a line back here and I'll see if I can help.

A photo or two showing how far you've got will also help

Steph

fredchong
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Re: TP90 tonearm repair

Post by fredchong » 18 Jun 2019 18:51

Hi Steph
Still no progress on changing the platform as I am unable to get the square block off . Attached are photos where I am at now.

Platform has cracked and broken to small pieces at two sides so glueing it back , I don't think will rotate smoothly . First 2 photos are the platform showing the broken spots.

I am thinking to use some heat as there might be some glue or loctite at the thread that is locking it..See picture of the square block thread that is very tightly screwed on.

Thanks for any useful tips from that anyone has disassembled the whole tp90.
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Vinylola
Sweden
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Joined: 16 Sep 2019 11:46

Re: TP90 tonearm repair

Post by Vinylola » 16 Sep 2019 18:56

Hi fredchong,

Any news on your progress?
I have exactly the same problem on a TP-90 tonearm for a TD-325.
Thanks in advance for any info or experiences.

Best regards,

Vinylola

StephDale
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Re: TP90 tonearm repair

Post by StephDale » 16 Sep 2019 19:59

Fredc, Vinylola,
I thought I'd answered this, my apologies to both of you...

You'll need to support the hollow tube at the bottom end, I just used the stock end of a drill that was a good fit, 3.5 or 4mm I think it was. You can then grip the end with a pair of pliers. The two parts are threaded together and have threadlock applied, but it's just a case of gripping well and then twisting in the correct direction to release the thread.

Of course, you'll need some threadlock such as Loctite 242 to re-assemble. If you've still got the wires in then it's a slightly more complicated job as your internal support needs to be a tube. I've done this as well, with small diameter stainless steel tube bought from a model shop or a well-known auction site.

When the parts come apart, keep track of how the bias magnet fits and don't worry about the bearings in the pillar; it's a sealed unit and they'll stay there.

Steph

Vinylola
Sweden
Posts: 2
Joined: 16 Sep 2019 11:46

Re: TP90 tonearm repair

Post by Vinylola » 17 Sep 2019 23:28

Hi StephDale,

Many thanks for the reply and info!
The plastic piece to replace is apparently called a “socket housing”.

I’m thinking of rewiring the tonearm (the thin wires that go from the deck to the headshell) while I’m at it. Do you think it’s worth the effort? If so, any recommendations on wires?

Thanks.

/Ola

StephDale
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Re: TP90 tonearm repair

Post by StephDale » 18 Sep 2019 17:36

I used AudioNote wire in mine, from here: https://www.hificollective.co.uk/wire/a ... -wire.html

With a well set-up tonearm it works very well. I left the original earth wire in place as it made life a bit simpler. The AudioNote wire was run from the headshell connector straight to the RCA terminals on the back of the turntable - I think the '325 has the same arrangement as the '2001.

I ordered half a meter, which gives me enough to rewire a headshell too. This is trickier, so I haven't done it yet. The wire is very fine and so you need to be very practised at soldering and able to do fast, clean, tidy work. I used WBT-0800 solder and a temperature-controlled iron to ensure compatibility with any existing solder.

Steph

jberger
Belgium
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Joined: 25 Nov 2004 09:06
Location: Brussels

Re: TP90 tonearm repair

Post by jberger » 27 Nov 2019 13:57

tp90brokenbasis.jpg
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i am sorry for my so late reply, i just read this post. This for FredChong
I experienced 2 things repairing Tp90.
1. broken basis = problem solved easily i just slice 1cm of a "connector water discharge pipe" inside diameter is exactly outside diameter broken basis both are pvc and stick well. Just 2 holes and paint in black. 10 years ago and still ok.
2. to remove cardan = just unscrew the hollow axis. My problem was the 'auto shut off' screen moving, this axis was unscrewed.

Jean-Jacques

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