Yes, sure.
Hi, @BigMax
I have a G1 800 SFF and when I flashed with moded bios I have experienced your situation. I have fixed the issue of don’t booting of my system by flashing the BIOS with an external programmer by a repair store with original bios file of HP site. I have fixed the issue of Ethernet card and I can help you to solve it. I also need your BIOS moded file to flash my pc to be able to boot from my NVME PCI adaptor. Tnx
@Xnet , could you please help me to find out why moded bios was corrupted? or how can I check the moded bios that be fine and equal to original bios from HP?
Hi @kamran2000 - could be many things in play. If I were to guess, you either inserted the ffs driver in a wrong section, either the tool you used messed it up (especially MMTool). If you post the file I may be able to see. Did the repair store give you a copy of the original ROM (16MBfile) before flashing the HP file? That could be repaired with the unmodded BIOS(10MB - if you still have it), and it’s better than the generic HP ROM. You’re probably running the Intel ME in factory mode now. If you don’t have that, you can still re-do the procedure to get the driver in and boot from NVME.
I just noticed now that yours is 800 SFF and not a mini DM. That model may have the BIOS sections a little bit different than the mini, and the numbers may not be the same as in my procedure. That could as well be the cause.
Tnx, the repair store used the original BIOS file from HP support website. Below link is the latest BIOS file from HP website for G1 800 SFF that I have uploaded. Could you help me to mode this original file to have NVME device in the boot menu and boot from it?
https://easyupload.io/kxjbva
@Xnet :
Thanks for >this< very useful step-by-step guide.
For a better usability/readability I have formatted it and hope, that this is ok for you. Otherwise you can restore the not formatted version.
@kamran2000
You may not be able to flash the full file with Intel Flasher. I checked and it seems its sections are the same with the mini. I extracted only the first A70000h and added the ffs driver in the attached zip. Flash it from Windows 7/10 64 bit with:
fptw64 -A 0x580000 -L 0xA70000 -F modBIOS-L01_0278.BIN
Let me know how it went.
modBIOS-L01_0278.zip (3.76 MB)
@Fernando
I can’t recall how it was before, but it looks crispy clear now. Thanks for doing it. I didn’t know you can alter someone else’s posts.
Xnet
How can I do "fptw64 -A 0x580000 -L 0xA70000 -F modBIOS-L01_0278.BIN"?
Is it any risk of black screen after flashing by this moded file?
Sincerely, by the questions you’re asking - there’s quite a big risk!
@Xnet
my hw is:
bios version & date : L04 v02.33 04/17/2019
ME Firmware Version: 9.1.45.3000
mini pc HP Elitedesk 800 g1 dm i5-4570T
system board id 1825
@Xnet
No 
. . .
I waited to see what the risks were because I had an experience with a motherboard that I couldn’t fix anymore.
Please give me exactly what bios I need to write from the ones that are here in the posts, so that I can test with my fingers crossed. Thank you very much for the prompt reply, respect!
@EDECAT
There’s really no big risk if you stick to the steps. Just do at least steps 1-6, and submit the BIOS dump. Let me know if you can write it back.
Thanks @Xnet
So, How can I do “fptw64 -A 0x580000 -L 0xA70000 -F modBIOS-L01_0278.BIN”?
I don’t have fptw64 software.
@kamran2000
I specifically wrote a comprehensive guide so an individual with basic computer skills can do that alone. It’s posted on page 4 of this thread. It’ll answer all possible logic questions. If you can’t follow that, ask a friend with basic PC skills or go to that repair store and ask them to do it for you.
@The-cube may help you as he promised to pay it forward. Just take it private.
Use jumpers on FD BB and PWD all 3 to bypass any restrictions
Just added nvme support to my Elitedesk 800G1 DM.
Don’t know what I did wrong first, but after bios modding I got a bricked PC.
After that I added the nvme module to the full stock bios and flashed it with a programmer, restored the MAC/PC serial numbers and everything is fine now. I see Windows boot manager (and my nvme SSD WDC SN520 256GB too) in the EFI boot menu and can boot from it to Windows 10.
Thanks for this great thread!
