hp elitebook 840 g4 need password unlock

[darkpower]

Re: hp elitebook 840 g4 need password unlock

Hello,
I tried to put a testing clamp on the bios socket, but did not work. The bios uses a Winbond 25Q128JVPQ and it has no leads. How did you do guys to reprogram it? Any help would be appreciated.
Thanks

[e900]

Re: hp elitebook 840 g4 need password unlock

send me pm or contact me on telegram @hansworst, then i show you pics

Hi

Im in the same position, would you be kind to share pics on the forum?
I have a soic 8 and the pins are short or above the contact points for the board.
My soldering skills are not great.

[ramzyharb]

Hp 840 g4 bios remove password

Hi guys help me need bios reset thats my dump

[peste]

Re: Hp 840 g4 bios remove password

try...

[ramzyharb]

Re: Hp 840 g4 bios remove password

Still need password

[peste]

Re: Hp 840 g4 bios remove password

try...

[ramzyharb]

Re: Hp 840 g4 bios remove password

Still locked

[peste]

Re: Hp 840 g4 bios remove password

your bios is corrupt, try it ...

[darkpower]

Re: hp elitebook 840 g4 need password unlock

mcplslg123

Thank you works perfect

Hello @zenek_19,
Did you remove the eeprom or is there any way to reprogram or without removing it? Please help me.
Thanks

[Vesko356]

Re: hp elitebook 840 g4 need password unlock

Hello @zenek_19,
Did you remove the eeprom or is there any way to reprogram or without removing it? Please help me.
Thanks

Best way is to remove the chip from the board, you can try to solder wires to the chip also, but this not always work with HP laptops. What is the problem, de soldering the chip from the board is not a hard job, even without the hot air station?

[RethoricalCheese]

Re: hp elitebook 840 g4 need password unlock

Best way is to remove the chip from the board, you can try to solder wires to the chip also, but this not always work with HP laptops. What is the problem, de soldering the chip from the board is not a hard job, even without the hot air station?

It has a WSON8 packaged EEPROM. Can't unsolder it without hot air.

[Vesko356]

Re: hp elitebook 840 g4 need password unlock

It has a WSON8 packaged EEPROM. Can't unsolder it without hot air.

If it's a WSON8 package bios chip - yes, the only option is hot air.

[darkpower]

Re: hp elitebook 840 g4 need password unlock

If it's a WSON8 package bios chip - yes, the only option is hot air.

Thank you guys for your help.

Regards

[darkpower]

Re: hp elitebook 840 g4 need password unlock

Hello Vesko356,
I'm actually afraid of breaking something on the mother board or something like that, do you have some advices/tutorials/other instructions to give me sothat I do it as safely as possible?
Thanks

[Vesko356]

Re: hp elitebook 840 g4 need password unlock

Hello Vesko356,
I'm actually afraid of breaking something on the mother board or something like that, do you have some advices/tutorials/other instructions to give me sothat I do it as safely as possible?
Thanks

About desoldering the chip with the hot air station? The job is not hard if you have some experience, if not just use some faulty motherboard to practice, it's a straightforward job, nothing special, just use good flux like AMTECH 213 or 559, use small or medium nozzle and not too much air (you can blow some small surrounding component if you use too much air), I would say half air ahd about 360 C will do the job perfectly.
P.S. Forgot to say - if you have surrounding plastic components, take care to cover it all with the kapton tape, or you will melt something very easily!
And last but not least pay attention about the chip position.

P.S.2 You can watch this youtube video for education, and how to do it.

[RethoricalCheese]

Re: hp elitebook 840 g4 need password unlock

I don't agree that you can blow away surrounding components with max air. The surface tension hold those components in place. You would have to physically move those components to make them fly away.

The only probleem is plastics melting. But on elitebooks, it is usually not a problem. On ProBooks, it is mostly a big problem. On this model, only the thin plasti under SSD will be deformed. Wouldn't call it an issue.

Just remove bios battery before soldering and you should be fine. It might take a while for the bios chip to start moving so please be gentle with the tweezers. Do not use force with the tweezers, it is pointless and harmful.

[PawelPL]

Re: hp elitebook 840 g4 need password unlock

Hi, can i try any of the files uploaded above for my 840 G4 and it will work or it has to be specific for individual machine? Thanks

[peste]

Re: hp elitebook 840 g4 need password unlock

put the bios backup here

[PawelPL]

Re: hp elitebook 840 g4 need password unlock

put the bios backup here

How do i do it? Thank you.
btw - my bios is locked, but can boot from usb...

[Vesko356]

Re: hp elitebook 840 g4 need password unlock

Hi, can i try any of the files uploaded above for my 840 G4 and it will work or it has to be specific for individual machine? Thanks

It's specific - serials etc., so first take a good verified dump of your machine and upload the file here for unlock. After that you can write unlocked file back to the bios chip.