2023-11-18: This story starts on eBay with the need for a new small computer...and ends with an auction listing I won for $300 on a used HP Elitedesk 805 G8 Ryzen 3 system (16GB/512GB)... I assumed I'd won it cheaply because it was poorly listed and didn't have the G8 label anywhere on the listing, except in the images...but I failed to notice in the description that there was a BIOS password until after I had the system and was attempting to update it for use. The first link I stumbled on seemed to be asking similar questions. Was he considering the same system I had just gotten? (and actually noticed the BIOS note?) Oh well, I can answer the questions for others now...
So the first request above is for a full circuit board picture to look for a CMOS Reset jumper. Here's the full board shot. This is for a 63C34UC HP Elitedesk 805 G8 Ryzen Desktop Mini PC
Bottom of the circuit board.
So here (blue box) is the CMOS Reset switch. Only it doesn't do what you hope. Remove battery and press/hold the button while booting the PC. It resets the BIOS defaults, but does not remove the BIOS password.
and just in case someone wants to know what is hidden under the sticker...
RTC Battery (Yellow Box). But not sure what this does exactly, except help the computer remember the time. Doesn't help with retaining EEPROM settings, that's for sure. And since we mentioned EEPROM...
And here are the EEPROM ICs... There are two of them - the Main BIOS (Red Square) and the backup BIOS (Green Square). Both chips appear to be MX25L25673GZ4I-08G. Datasheet here. (PDF, 1.5MB) Notice anything fishy about the main BIOS? Yeah, I tried de-soldering it. I can't lift the chip off the board - it has a large solder pad in the back center of the chip; you can't use a soldering iron to remove it, you need a hot air rework station and I don't have one. I've also tried getting my ROM Programmer clips on there and can't get a firm connection. Blue box is the 'Flash Descriptor Override (FDO)' Jumper. Magenta box is the 'Boot Block Recovery (BBR)' Jumper. Strikeout here without additional equipment.
We can still boot into windows. Let's check if it needs updates. System had been wiped to Windows 10 x64 booting via UEFI. Current Firmware is T26 02.08, Oh good, Firmware update to 02.09 available via SP148025.
And...the HpFirmwareUpdRec requires you to enter a password to update the BIOS... Why? It does appear to allow unlimited guesses unlike the BIOS password prompt. [insert hours of wasted time with a debugger] It would also appear this little program checks to see if debuggers are active [and crashes with unhandled exception if there is one active] and also does a hash check on itself [and exits if it fails]... Sigh... Windows has waiting updates? Why is there a BIOS update to 02.09 in the list?
Is there a method to this madness? Windows can install a BIOS update (without a password prompt) but HP's own utilities can't? Let's go through the BIOS reset process to check on the new 'Clear BIOS Passwords on RTC Battery Removal' feature.
Sigh... no change - BIOS password still active. It appears that the default is 'Disabled'. Redacted BIOS Settings export file (txt, 13kB) Just in case you didn't know, you can get the BIOS settings from HP Elitedesks by running BiosConfigUtility /Get:[filename]. This tool is available from HP as SP143621.
Here is a brief explanation of the function and also confirmation that the setting is by default set to 'disabled'. You can browse the full document here: HP PC Commercial BIOS (UEFI) Administration Guide (PDF, 1.47MB)/p>
And there is this weird little setting tucked away in this list as well... What does it mean? Is there actually a reset jumper?
FYI: this does not work - don't try it. If you attempt to power this little EEPROM through your reader, you are attempting to power the whole power rail for the circuit board. My programmer (XGeco Pro T56) does not output enough power to do so and I'm glad it errored out with an over-current fault before attempting to back-deliver all the needed power through tiny traces.
Here is a link to the HP Elitedesk 805 G8 Maintenance and Service Guide (PDF, 1.67MB). There are a couple interesting chapters to look at for a little more information on this computer. Chapter 8 is about Password Security and resetting the CMOS (not helpful at all). There's also an interesting chapter 11 about Memory Volatility and all the different memory locations in the computer. Again, not super helpful, but interesting.
Since this is Windows 10 x64, I have limited access to older tools in Windows. And since this is still setup for Secure Boot/UEFI, I have limited access to what boot discs I can use. Hiren's BootCD PE boots for example, but the BootCD 15.2 cannot. (sigh no CMOSpwd yet).
[work in progress - still gathering additional information]
Corrections & Additional Information are welcome... Please let me know if you see mistakes!
And as always, clicking on an image will give you a higher-res version! If you repost or further dissect this board, please link back to the original and let us know where we can read about your work!