hp elitebook 840 g4 need password unlock

[peste]

Re: Hp 840 g4 bios remove password

try...

[ramzyharb]

Hp 840 g4 bios remove password

Hi guys help me need bios reset thats my dump

[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.

[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

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

I'll have a look - there's a strong possibility the bios chip isn't sat quite in the right place - it just sits on top of the board rather then having legs going through it - so getting it in the right place seems like a bit of hit and miss...

[SMDFlea]

Re: hp elitebook 840 g4 need password unlock

It looks like you`ve knocked a part off the board.Check the traces as well for continuity,you might have cut through one of them.

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

I managed to get it off the motherboard and flashed it using my Pi - unfortunately on reconnecting everything the laptop doesn't turn on - so I guess I've messed something up somewhere.

I may give up.

The power light (the main one on the switch) and the Caps Lock light go off then come on again in a cycle.

I've had a hunt for whether this means something but am find mixed answers.

[RethoricalCheese]

Re: hp elitebook 840 g4 need password unlock

Either you need to unsolder it or solder wires on the large pads around the chip.

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

I'm obviously new to all this and doing things the wrong way.

The clip I'm trying to use is attached to a Raspberry PI - I thought that gave it all the power it needed ?

In the hope of getting to the bios chip a bit better I've removed the motherboard.

I've take pictures of the chip - I've no idea how to get a clip on this so contact is made correctly and unsure whether I can heat gun the chip off the board.

Has anyone any experience of dealing with a similar chip ?

[RethoricalCheese]

Re: hp elitebook 840 g4 need password unlock

If you want to read HP eeproms onboard with a clip you need to first unplug battery. Plug charger. Turn on laptop (go to F1 screen or bios, doesnt matter). Turn off laptop but keep charger plugged in. And now connect your clip and programmer. This way it almost always works fine.

But the one you sent a pic of is not correct. It is the other one with 128 written on it, not 64.

[SMDFlea]

Re: hp elitebook 840 g4 need password unlock

send me pm or c**********************ow you pics

assistance is best done in public

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

send me pm or conta**********ct********hen i show you pics

Pm’d - many thanks

[Nico Latour]

Re: hp elitebook 840 g4 need password unlock

BANNED

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

840 g4 chip is left near the bios battery (you can desolder or use old soic clip and cut off small plastic and hold on pads near chip

I'm still on this - I can't get the SOIC clip to connect - what bits are you suggesting I cut off ?

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

I've attached a picture of the chip ... does this look correct ?

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

Perfect - thanks guys - I thought that was the one - I’m trying to use a clip but having a few problems - I’ll try again :-)

[Nico Latour]

Re: hp elitebook 840 g4 need password unlock

840 g4 chip is left near the bios battery (you can desolder or use old soic clip and cut off small plastic and hold on pads near chip

[RethoricalCheese]

Re: hp elitebook 840 g4 need password unlock

Did you even open up the laptop?

There are 2 EEPROMs right next to the RTC battery. I think they are in WSON8 package on that model so unless you have a better way, they must be unsoldered to read/write.

Anyway, the larger sized EEPROM is main bios. Probably 25Q128 written on it.

[GrahamA]

Re: hp elitebook 840 g4 need password unlock

Can anyone tell me where the bios chip is on the HP Elitebook 840 G4 ? I've trawled through the service manual but can't see it referenced anywhere.

Any help greatly appreciated.

[ismailweb]

Re: hp elitebook 840 g4 need password unlock

this

thanx