HP9816 keyboard plunger wanted.

David Collins davidkcollins2 at gmail.com
Sun May 28 16:34:12 CDT 2017

Mattis, the problem you have is very common on these and HP85 keyboards and is usually caused by one side of the square plunger cracking in a corner and bowing out. 

It's normally fixed by gently bending the affected side towards the centre of the square. A little bit of heat from a hair dryer while bending helps it stay in place. Be careful when you reinsert the keycap so you don't bend it out again. 

Although it's not really recommended as it can attract dust, I also give the plunger a squirt of silicone or WD40 to keep it moving smoothly. 

Hope that helps. 

David Collins
HP Computer Museum

> On 29 May 2017, at 1:50 am, Mattis Lind via cctalk <cctalk at classiccmp.org> wrote:
> Hello!
> I recently received a HP9816 machine. The previous owner originally got the
> machine without a keyboard but subsequently sourced a keyboard off ebay.
> Unfortunately this keyboard was not in the best shape. One key was stuck
> and when taking it apart it was evident that it has taken a bath for quite
> some time. At least the electronics around the space bar were quite
> affected with corrosion. Luckily this keyboard is quite simple design with
> only CMOS 4XXX IC, and better yet, Tony Duell has already reverse
> engineered it (together with the rest of this little machine). Thanks a lot
> Tony!
> But the stuck key appeared to be cause by the "plunger" (is that the
> correct english word?) is slightly cracked in the corner. When the keytop
> is inserted it is not sliding very well.
> I have not found a method of repairing it so I am asking the community if
> there are anyone that has spare "plungers" for the HP9816 keyboard.
> http://i.imgur.com/q5aRQnC.jpg?1
> http://i.imgur.com/67xWZ8q.jpg?1
> http://i.imgur.com/cGWCKFw.jpg?1
> This is the keyboard at the hpmuseum.net page:
> http://www.hpmuseum.net/images/200serieskeyboardsmall-35.jpg
> /Mattis

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