#%&_at_! more compaq...

From: jpero_at_pop.cgocable.net <(jpero_at_pop.cgocable.net)>
Date: Thu Jul 23 11:57:14 1998

> Date: Thu, 23 Jul 1998 01:05:55 +0100 (BST)
> Reply-to: classiccmp_at_u.washington.edu
> From: ard_at_p850ug1.demon.co.uk (Tony Duell)
> To: "Discussion re-collecting of classic computers" <classiccmp_at_u.washington.edu>
> Subject: Re: #%&_at_! more compaq...

> >
> > I am sorry, but I really have to ask this before I do anything else.


> > again. What should I do? I can't replace the ribbon because the whole
> > keyboard circuit board is one piece of plastic film (two layers).

I know stupid green with grey/black traces very well, they're really
a bitch to handle and they're very poor when it get wet causes
corrosion in few days rendering some types useless especially those
that are one-sheet multi-layer designs.

These are typical semiclear poly sheet that has grey conductive (like
a ink) traces and pads silkscreened right on there. Sometimes
denpending on design requirements uses folded sheet with a insulating
sheet with holes at right locations to keep switch contacts apart
at specific distrance by that thickness of this poly sheet. As in
PS/1 keyboards. In other keyboards, usually uses one sheet with
layers of conductive ink printed on then insulating green
silkscreened on it to permit another layer of conductive ink and
final insulating printed on, sometimes some designs uses itself as
contacts or use carbon ink just for the contacts itself.


Don't - (snip!) oh no, too late!

After all those blue streak cursing settled, be prepared to curse
again, butched that one really good. You can't make it longer again
for ever. And this keyboard is unit replacement and usually costs
more than what this laptop is worth direct from compaq. Yes, still
can get parts for most older notebooks.
Other sources, you can ask and surf on that newsgroups and websites
until you find a used keyboard or another broken notebook.

These cracks in that grey traces CAN BE repaired with a
conductive pen. I use mine product called "Circuit Works" for this.

I kept my LTE 386s/20 keyboard alive on that narrower one of two set
cables for years and the repaired sections is still flexiable.
My method: clean real good and insure that traces is not insulated
by another sticky tape. Glop some conductive ink on in a way that is
easily clear any shorts, let dry for few hours. Scrape to make new
traces as originally designed.
Need to keep that black part because this is better material for
making connections in that locking connectors. That why you snipped
that off and that is far too short. I did once but I only merely
very tiny trimmed it if asolutely must. For anything else, I merely
dab on with a wetted end of blunt slim objects. Oh, you can't
solder because of that poly sheets.

TIP: unscrew that applicator off that pen after shaking that pen
until that steel ball rattles and stick the tool of your choice in
there to get some load of that grey stuff instead of it's built in
applicator. It dries real fast so you have to transfer that
conductive ink direct from that pen to the work.

> How about making an extension cable? If it's the sort of tapewire that I
> think it is, the 'edge connector' is a standard part. And you can buy
> straight pieces of the cable - a little hard to find, but you can
> sometimes raid them off old printheads. Solder the pins of connector to one
> end of (say) 2" of tapewire and plug the whole lot together.

Too different between 2 due to pin pitches. :-( tapewire and that
printed on sheets. But thanks for this tip, I was wondering where to
find them as I sometimes need them to make new cables or create new
adapters ie: LTE 286 to replace the clobbered 3.5" hd for a 2.5" hd

> Whatever you do, don't bring a soldering iron near the keyboard flexible
> PCB. It will melt, and fixing it is not fun.

Oh you jumped in there first so that is fine with me. :)

> -tony

Jason D.
Jason D.
Received on Thu Jul 23 1998 - 11:57:14 BST

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