Elitebooks (820, 840 etc. all gens) and those continuously flashing Power LED + flashing CapsLock LED

[STKR123]

As the Elitebooks (820, 840 all gens) only show flashing Power LED and flashing CapsLock (continuously) + a very soft "ticking" noise near the DC Jack,
I wonder if re-flashing the BIOS might be of any use here.

As far as I understood, steady flashing either means insufficient power or a CPU/GPU/Motherboard issue. I use the original 65watt power supply.

There are so many threads out there, but most of the solutions involve flashing codes, which I dont have or claim that you MUST use the original power supply, do a hard reset, reseat the RAM, clean the RAM, remove everything including the RTC battery and so on.
Nothing helped.

Do 820, 840 Elitebooks require a battery to be attached? I dont have batteries.
I also read that "some of these (hp) battery-connectors require a "physical connection", so they thinks there is a battery attached?


I have a Elitebook 820 (Gen1) here, with these flashing LEDs.

BIOS "Crisis Recovery" Win+V or Win+B wouldnt do anything, just the flashing LEDs


Also, which chip would be the BIOS here?

After reading some more into it, I purchased the "standard black" CH341A USB with a clamp and adapters.
Which adapter would I need to use toghether with the clamp and how? I read the clamp wont work on some "feet".

And would there a additional way to tell if it is the CPU/GPU or Motherboard?
For desktops I used PCI cards back then, that showed an additional "error codes" in red numbers for example.

Thank you in advance.

[STKR123]

Using a noname (Yisbat) 65W Adapter 19,5V 3,33A the 820 turns on instantly every single time.
Still showing the CMOS Checksum error, but what do these Elitebooks are looking for?

Also I stumbled across this "shortcut pin 7 & 8 on BIOS chip while beeing in the System Info Screen -> F1 -> F10 = Voila.
Im scared to try it though.

https://www.youtube.com/watch?v=kc4lIC-EsaE

[STKR123]

By now it has the look and feel, that it might be indeed connected to the powersupply. My original HP power supply seems to be faulty.

Using a very old 19,5V 3,3A DELL powersupply today, 1 out of 100 tries it suddenly switched on, showing a CMOS checksum (502) error.

This still does look like bad HW though, but I will order one last original HP power supply for the 820.
It wouldnt surprise me if it would work, but Id really like to know why then.

It also looks like as if the clamp might fit the BIOS chip(s). But I got to read more into it.

[STKR123]

Using a noname (Yisbat) 65W Adapter 19,5V 3,33A the 820 turns on instantly every single time.
Still showing the CMOS Checksum error, but what do these Elitebooks are looking for?

Also I stumbled across this "shortcut pin 7 & 8 on BIOS chip while beeing in the System Info Screen -> F1 -> F10 = Voila.
Im scared to try it though.

https://www.youtube.com/watch?v=kc4lIC-EsaE

[loopster]

Go for it, it works. I just tried it on a Probook 640 G1 I am not using very much, and it does indeed clear the Bios password.
I needed two attempts to pinch the 7 and 8 pins correctly with my tweezers, other than that, it is as straightforward as in the video. The chip doesn't seem to mind if you don't get it right the first time :-)

[STKR123]

I just realised I have a Elitebook 820 without the G1 on the label. So it is just a 820. (?)

But yes, it worked indeed!

I guess 840 G1 and 840 G2 wont like this "technique"? Also these do have 2 BIOS chips?

[loopster]

One is the EC Bios chip, the other one is for the main Bios, which is the one to be "treated".
Can't try, don't have any, although I've got many hp machines :-)

[STKR123]

Could be 1st and last try though.

Sadly those old masterpassword-times, like "lkwpeter", are long gone. ^^

I also stumbled across the Master Password Generator on github, but I guess RCUnlocker is the way of choice for Elitebooks 820 and 840.
https://github.com/bacher09/pwgen-for-bios

Will have to check. Haven tried multiple wrong passwords in a row yet.


This youtuber shortcuts the CMOS battery pins. (battery not connected) I guess that would be the same as keeping the power button pressed for 30 seconds?
Also I thought CLRCMOS (incl. jumpers) do not remove any passwords anymore?

https://www.youtube.com/watch?v=9tp2NpcuWIU

[STKR123]

loopster
Which chip does your ProBook 640 G1 have? The 25L12873F "SOP8" ?

What worked on a EliteBook 820 G1 chip (25Q128A) "SOP8" fails on a EliteBook 840 G1 (25Q16DVSIG) "SOIC8".

Seems like PIN7 & PIN8 shortcutting only works on 25x128xxx but not on 25x16xxx

As far as I understood SOP8 and SOIC8 are basically the same though.


An EliteBook 840 G2 has 2x Winbond. 1x 25Q128FVSQ and 1x25Q16DVSIG for example.
But it does NOT work on the 25Q128FVSQ.

[loopster]

Yes, mine has 25L12873F 8-SOP

[STKR123]

Seems like the CH341A BIOS programmer (black) is already suffering from all the plugging. :S
Working now. But I get a "Missing unlockable content" when using RCUnlocker.

I tried reading a "25L12873F" on a 840 G2 with NeoProgrammer, which already came with a 2020 BIOS.
While reading it, NeoProgrammer says "Disconnected / not responding" and "Detects" it as different chip every time.

So, as this 840 G2 has the "25L12873F" instead of a "25Q128FVSQ" I tried shortcutting Pin 6 and 7.
But it does not work. Probably got fixed, as it is a 2020 BIOS already?

Laptop boots up normally.