Keyboard problems

[AlexKrk]

Some time ago I had a problem with some keys (g, h, backspace, left, down). They periodically partially do not work (when pressed, nothing happens, or can perform several actions at once). And the problem is not in the keyboard. Because the keys behave very strangely. In Windows in one window they do not work, and when switching to another window, they start to work, but then they can stop. When booting from Live CD, the problem also exists, but it occurs much less often. For some time, resetting the BIOS by disconnecting the CMOS battery improves the situation. How to solve this problem?

HP EliteBook 840 14 inch G9 Notebook PC

U71 Ver. 01.13.00 - 11/21/2024

KBC Version 20.74.00

Windows 11 (23H2, 24H2)

[Jupitero]

Hello.

Sounds like your keyboard is broken since the problem exists outside Windows.

Working keyboards do not have these kind of problems at all.

I recommend taking your laptop to a HP service partner and have them confirm my diagnosis and replace the keyboard.

[AlexKrk]

Usually a faulty keyboard does not type at all, or duplicates characters. And this is reproduced constantly. In my case, everything is the other way around. And how can I explain that resetting helps for some time? Also, the HP keyboard test shows that there are no problems with the keyboard.

Judging by the messages, I'm not the only one with this problem. Some of them say that replacing the keyboard does not solve the problem. Here's an example:

1. https://h30434.www3.hp.com/t5/Business-Notebooks/Keyboard-for-Elitebook-845-g10-doesn-t-work-properl...

2. https://h30434.www3.hp.com/t5/Business-Notebooks/A-few-keys-on-EliteBook-8770W-keyboard-have-stopped...

[Jupitero]

Hi,

Usually a faulty keyboard does not type at all, or duplicates characters.

Broken hardware does not always misbehave consistently. Easiest way to diagnose this would be to change hardware parts, starting with the keyboard. The keyboard may look like a dummy piece of kit but it has electronics inside. Perhaps there's some conductive traces that have broken and only work intermittently due to thermal changes or from the pressure from user's keypresses. The fault could also lie in the laptop system board connector or other electronics.

The HP keyboard test is rather simple in my mind and does not test the keyboard circuitry, just that it is connected. It is handy for testing all buttons separately though.

About your examples: 8770w is from 2012, with different keyboard and electronics. 845 G10 also has a different keyboard part to your 840 G9.

I'm not sure what you want to hear. To me this is clearly a hardware problem because the keyboard failed in Linux as well. I'm still recommending you to take the laptop to HP service and let them give their diagnosis.

As a last resort you can always try a "power reset" per HP instructions:

https://support.hp.com/lv-en/document/ish_1997208-1551050-16