Broken trackpoint stem

kousuke

25 May 2017, 02:16

Greetings,

Trying my luck here as I had no response at geekhack

Trackpoint stem on my beloved KPH0035 IBM USB spacesaver keyboard which I'm primarily uses for work is broken :( it is a BOURNS 3722B based trackpoint module - see attachments below

I'm wondering if this is repairable or I actually have to replace the entire module?

Not quite sure where I can even find spare part for this

Thanks in advance
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kousuke

25 May 2017, 02:54

I'm thinking of using epoxy putty for the repair - it looks like abs plastic - I don't understand how does the sensors circuitry works - kindna worried that gluing the pieces back would not actually reconnect the circuit?

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rsbseb
-Horned Rabbit-

25 May 2017, 03:01

If it is ABS it could be solvent welded back together. The solvent glue for doing such a repair can be found in just about any home improvement center. I'm not familiar with your component though and am uncertain about any measure of success you would have. replacement might be a better option as it looks like there is a conductive surface applied to the bottom

How did you manage to break it?

kousuke

25 May 2017, 03:05

Damn.. looks like gluing it back together is not going to fix it :shock:

There are wire traces underneath it and they have torn off...
trackpoint wiretrace.jpg
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What a shockingly stupid design...
Last edited by kousuke on 25 May 2017, 03:13, edited 1 time in total.

kousuke

25 May 2017, 03:10

rsbseb wrote: If it is ABS it could be solvent welded back together. The solvent glue for doing such a repair can be found in just about any home improvement center. I'm not familiar with your component though and am uncertain about any measure of success you would have. replacement might be a better option as it looks like there is a conductive surface applied to the bottom

How did you manage to break it?
Thank you for responding

I actually bought the keyboard off ebay and it arrived broken - I paid a fortune to have it shipped from U.S. to Melbourne Australia

It's going to cost me heaps more to ship it back for return... hopefully I get a partial refund while I hunt for spare parts..

Sigh...

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rsbseb
-Horned Rabbit-

25 May 2017, 03:11

A quick search resulted in an article explaining the tech behind your part. It is made of a ceramic material not ABS so scratch my previous recommendation. below is a link to the article which includes contact info for the manufacturer. They may be able to provide a replacement or send you to a vendor who can. ;)

kousuke

25 May 2017, 03:25

thanks I did find that link - it dates back to 1998 and the part is no longer in production - I have contacted BOURNS for spare part - I doubt they still have it in inventory

kousuke

25 May 2017, 03:38

Does anyone knows if the PS/2 cousin - IBM RT3200 / 37L0888 uses the same part for the trackpoint module? I'm hoping to savage the parts from a working keyboard

kousuke

25 May 2017, 05:26

found the IBM patent

ceramic strain gauge
https://www.google.com.au/patents/US6195082

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