27 Nov
2025
27 Nov
'25
2:58 a.m.
Good, let us know how it works out !
On Thu, Nov 27, 2025 at 6:08 AM me--- via cctalk <cctalk(a)classiccmp.org>
wrote:
Someone else responded directly with me and the same
suggestion but
provided
a link on amazon.
So, I'm going to go with both your suggestions.
Thanks,
Daniel
sysop | Air & Wave BBS
finger | calcmandan(a)bbs.erb.pw
On Wed, 26 Nov 2025, Adrian Godwin via cctalk wrote:
I don't know what the internal construction
of the TRS-80 keyboard is
but
there a number of products targeting remote
controls with a
conductive-rubber bubble over a gold-plated pcb.
These vary between paints, entire keypads and small conductive rubber
discs
which cover the original rubber patch. As long as
the bubble hasn't
cracked
but only the conductive material has worn thin,
these last seem as though
they might be the best and least invasive repair option. Easily available
on ebay, some from reputable suppliers - maybe chemtronics ?
https://www.eevblog.com/forum/repair/best-method-to-restore-conductive-keyp…
On Wed, Nov 26, 2025 at 1:10 PM me--- via cctalk <cctalk(a)classiccmp.org>
wrote:
> I just acquired a TRS-80 model 102, my first of that model.
>
> Everything is great other than three keys. The 2 keys works
> intermittently,
> q, and [ don't work. Having checked the schematic, the keys have no
> commonality on the circuit.
>
> Before I pull the cap off the switch, I know that the rubber dome inside
> has
> material on the inner part that meets with the silver contacts to
complete
> the circuit. I'm told this material will
wear out or lose conductivity.
>
> I reflowed the solder joints on the pcb and this didn't help. Other
people
>> have simply replaced the rubber dome from another dead 102's keyboard.
>> But,
>> I'd rather attempt applying new material inside that dome.
>>
>> I'm hoping there is an inexpensive and mainstream solution I can buy at
>> home
>> depot or something.
>>
>> Any tips?
>>
>> Daniel
>> sysop | Air & Wave BBS
>> finger | calcmandan(a)bbs.erb.pw
>>
>