HP Probook 640G2 BIOS Update Failure

If you can offer any advice I truly appreciate it. I have an HP Probook 640G2 I acquired from a friend some months back. I recently updated the BIOS from 1.21 to 1.33 and experienced a failure. Upon the next boot I got no video and the 2 long 2 short beep code indicating BIOS corruption. I had no luck with BIOS recovery at first and now understanding why have made a bit more progress. I wiped the internal SSD completely (removing the recovery BIOS files) when I purchased the laptop in order to remove anything the previous owner may have installed. ..

Today I happened upon the information re BIOS recovery folder structure and have created a USB with the correct folders and copied the N76_133.bin file into the appropriate folders (current and new). Now the laptop boots, read the key, flashes the HP logo screen and promptly reboots. It appears to be doing SOMETHING but isn't making it to the recovery. Again any advice is appreciated.

Thanks

 

Thanks for the links and quick response. I have now tried using that tool from HP (again thank you) with the same results, boot without beeping, read USB, display HP Logo and reboot.

I ordered a programmer and test clip from Amazon, they arrive later today. I've read the links you provided and now have a bios image for a 640G2 N76 Rom. One post mentions different size ROMs for different 640G2 but I believe mine is the same size as the ROM I got from ghostlyhaks so it should be all good. Is there any specific software I should use with the programmer? It does not appear to come with any and I've seen differing opinions on which to use. Again, any flashing advice appreciated!

Thank you.

 

Thanks for that info...hate to ask but what schematics and where would I get a 1.8v adapter? Would the test clip still be usable?

 

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I've just finished getting drivers installed in Win 10 1803 and trying ch341a 1.29 and 1.30 in another HP laptop that it turned out had a faulty USB 2.0 port but the 3.0 worked fine (kept getting verify errors). Moved to my desktop and loaded the N76_133.bin from HP update, erased and wrote to chip. Now I have only a flashing amber power light when connecting AC or battery. Any ideas out of this dead end?

 

Moved to Linux and flashrom correctly identifies my Winbond chip! I've read and verified BUT this after already writing from Windows and getting the blinking amber light. I did read a few backups from Windows, and I have the HP Bios update, how can I combine the two so I don't lose all my information but still write the bios itself back to the chip?

 

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- Yes they are markedly different, its like my backup was barely half of the BIOS. And now since I've flashed it with other BIOSs there is no going back to get a good backup Except on that drive.
Turns out that HP like many are using a proprietary algorithm to manipulate the password user enters prior to executing the secure-set command on the drive. I have an elitebook 6475b with updated BIOS that may unlock it but I need to get an m.2 to SATA adapter first.

 

Can you elaborate a bit on that? I really want this back but at the moment am in midst of a clinic opening on a couple of weeks and I'm the virtualization-windows server-gpo-802.11wireless-hipaa compliance and documentation-encryprion-mail-desktop-etc guy. I'm busy but in need of the laptop. I guess just need to know what key you mean, and why do you think other dumps aren't booting once flashed?

I got an elitebook and using a 3rd HP set drivelock and unlock with new elitebook. Their algorithm is same for last few years. My SSD was locked with bios admin and yet I still cannot unlock it. I must have used a new "secure" password that thanks to biometric i don't remember.

 

I'll look at the board later today. I had it written down but can't find it...No I didn't put the old partially downloaded bios in the Previous folder but I can try that. You meant the one I got part of, yes? And yes I am only using flashrom now, under Linux seems more reliable.

 

LatinMcG thanks for validating what I've been trying. I have followed this protocol with exception of using the old bin file in the Previous folder.

Regarding the full dump, I've flashed (succesfully) 2 or 3 dumps obtained from GhostlyHaks and here but the laptop will not turn the display on even. One causes same beep codes and behavior, another simply high speed fan and reboot cycling. Any ideas why and do you know where to get another?

 

Done. The resulting BIOS allowed me to boot, unlock my SSD (and eventually remove Drivelock) and get back to using my 640G2. As it turns out Drivelock is backwards compatible, but not forwards and there are changes between the Elitebook 745G2 and the Probook 640G2. A guide will be published in the next few days as time allows on my website. I'll post back when its up.