interesting HP 25 keyboard fault

[dmh]

I just had a look at an HP 25 which looked good except for 2 keyboard faults.

The '5' key didn't always register and I've received lots of suggestions for resolving that when I posted about my HP 21 models. I assume the 25 will have holes in the back of the keyboard too.

The other issue was a bit more interesting, the '4' sometimes generated a '4' as expected but other presses it would generate a '6'. If you tried to type in '44444444' you would get something like '46446646'. It was actually entering '6' as calculations gave results based on this (so not a display issue).

Is this a common problem and more importantly, is there a simple fix?

When I opened my 21 the traces for the number keys were vertical so how is this possible?

Just wondering if it's worth the risk of buying it and hoping the issues can be repaired easily (without pulling the keyboard apart).

TIA, dmh

[teenix]

(02-18-2021 05:28 AM)dmh Wrote:  I just had a look at an HP 25 which looked good except for 2 keyboard faults.

The '5' key didn't always register and I've received lots of suggestions for resolving that when I posted about my HP 21 models. I assume the 25 will have holes in the back of the keyboard too.

The other issue was a bit more interesting, the '4' sometimes generated a '4' as expected but other presses it would generate a '6'. If you tried to type in '44444444' you would get something like '46446646'. It was actually entering '6' as calculations gave results based on this (so not a display issue).

Is this a common problem and more importantly, is there a simple fix?

When I opened my 21 the tracers for the number keys were vertical so how is this possible?

Just wondering if it's worth the risk of buying it and hoping the issues can be repaired easily (without pulling the keyboard apart).

TIA, dmh

If the key contacts are dirty or corroded, they processor might interpret them incorrectly. Maybe a good clean up will fix it.

I assume you mean the circuit board traces, on the other side of the circuit board there will be horizontal traces.

cheers

Tony

[dmh]

Thanks.

Are there holes in the back of all 25 keyboards for cleaning or most or only some?

I've seen some woodstocks discussed that don't always have holes.

[isanchez]

Hi,

use Deoxit: IN THE BACK HOLES, not through the front side. Just a drop through the golden hole. and press the key repetidly. Repeat the process if necessary.
Be carefull: do not allow this product touch the front side (it can be aggressive with the printed letters and there is no access to the problem through this side), just a small amout through the inner side holes that correspond with the non working keys.

Good luck

Ignacio