Elitebook 850 G5 BIOS bricked

[achim6]

I have an Elitebook 850 G5 which was bricked by a BIOS update. When turning on the laptop, the power and wifi front lights turn on and the fan starts spinning, but I don't get any image on the internal display or an external screen.  The support document at https://support.hp.com/us-en/document/ish_3932413-2337994-16 suggests that there is an "Automatic BIOS recovery" which - if I understand this correctly - is simply using a previous version from a hidden partition on the SSD. The laptop currently doesn't have a SSD anymore. I could insert a blank one or prepare one with an ISO image or something like that if it would help. Or is there another way?

[TzortzisG]

Hello achim6.

Bricked laptops due to incidents during the BIOS upgrade are almost impossible to "fix" on modern or semi-modern systems. Anyways, I consider this as the mother-document since it contains links to the one you found and also this second relevant one: 500, 501, or 502 error. The procedure you're looking for is at the bottom of both pages, using a USB flash drive. It can't hurt to try this, but as mentioned above chances are very very (very) slim to none. If this fails, externally flashing the BIOS chip with a "good" firmware is the only method known to salvage a notebook in this state....

[achim6]

Well, thanks for trying to help. I tried the USB stick, but it didn't work.

[TzortzisG]

Yes, there's no point to trying these methods on anything past a G1 Business laptop.

The UEFI firmware code is too complicated on newer systems, so when a BIOS update goes wrong the code is completely corrupted and you might as well have a new completely clean BIOS chip on the motherboard. For these methods to work, you need a small fraction of the code (the first lines) to still be OK. Anyways, I have discussed this some years ago on a previous thread: https://h30434.www3.hp.com/t5/Business-Notebooks/Caps-Lock-and-Num-Lock-Blinking-5-Times/td-p/871318.... You can still save this system by externally flashing the chip, many stores do this nowadays, as you can imagine this is a very lucrative business (with the whole Windows Update pushing BIOS upgrades on the sly thing).