On powering on my laptop it boots into system diagnostics after the hp loading screen every time

[JJKxGOJO]

I am using a Elitebook 840g3 with win 10 64bit in it. When i power on my pc it goes straight into hardware diagnostic UEFI. I can then manually escape it and continue to boot to win 10 but still some time it gets back into it even after a try to escape. I started getting this after I had removed another OS that I had along with win 10 before that I had option to get into either os. I tried lot of ways to fix this like resetting bios settings, updating most of the related drivers, unchecking safe boot etc. This issue is so annoying kindly help asap

[Jupitero · Accepted solution]

Hello.

The UEFI diagnostic is invoked by pressing F2 during boot. Does your F2 button function normally? A stuck key could cause this.

[JJKxGOJO]

Appreciate the reply. I don't think that's the case there isn't any problem with the f2 key. I Tried disabling the key but still it does the same and now some time I am not being able to navigate to exit as selector climbs back to the first option 

[Jupitero]

Hi,

Can you tell me how you disabled the physical F2 key on your keyboard?

If you have an external keyboard, disconnect it.

The selector is moved by keyboard, so if it moves by itself, I am quite certain that the keyboard is causing this. I would first try reseating (reconnecting) the keyboard cable(s) in case the connection is faulty. You can try this at home, HP has designated this as "Customer Self-Repair" job but if you are unsure, go for a (HP) laptop repair store, they have the knowhow.

If you want to try this, the Maintenance and Service Guide for Elitebook 840 G3, page 50 shows how the keyboard is replaced. Be careful when taking the keyboard out because the 2 or 3 cables connecting between the laptop and keyboard are quite short. The cables can also be a bit difficult to insert back into the connectors...

You can also try booting with the keyboard completely disconnected but you'll probably need an external keyboard to bypass possible keyboard error message during boot.

[JJKxGOJO]

Hello , I disabled my f2 key with a remapping software called sharpkeys and my f2 key is no longer functional and sorry it didn't move on its own the page was reloading resulting the selector to reposition to the top. My external keyboard is perfectly fine I am using it with other devices. I can use my f2 button with external keyboard but not with the in built  now. My inbuilt keyboard has problem with its Rshift so I have it disabled. I will try what you said if that's what i have to do. Thank you

[Jupitero]

Hello.

Remapping any keyboard keys in Windows only affects the keys in Windows. The remapping does not affect the keyboard until Windows loads: during bootup when HP Logo is shown or in the HP UEFI diagnostics the F2 will still work as F2 should.

If in your case the F2 button is faulty and invokes the black UEFI Diagnostics screen, only way to confirm that fault would be to disconnect any external keyboards and to disconnect the internal keyboard cable.

[JJKxGOJO]

Well if that's the case then what should I do?. Do i need to disable or replace the whole built in keyboard or can I disable the f2 key alone and i have a doubt if the f2 is malfunctioning then on holding the fn button shouldn't it do  it's function when I am in windows. It does nothing even before i disabled the key

[Jupitero]

Does your F2 button have and alternative function? Quick web search shows that the F2 on 840 G3 does not have any symbols on it, so F2 works always works as an F2 button, whether Fn is pressed or not.

If the F2 key is physically broken, there is no other way to fix it than to replace the keyboard. If there is debris underneath the keycap holding the button down, the keycap can be pried out and cleaned. HP has an instructional video showing how keycaps can be removed and cleaned.

In Windows the F2 button is quite easy to test - select a file and press F2. If you can then rename the file, the button worked. If selecting any file always tries to rename files, then the button is stuck. So please undo the F2 button remapping you did earlier and check for this.

[JJKxGOJO]

Hey thanks. You were right about f2key it is the cause of the problem and it also ask me to rename the file on selecting one