Hi guys,
If someone would be able to provide some expertise, I'd be very grateful.
BIOS Corruption - Cause
So I managed to corrupt my machine by installing linux and enrolling custom secure boot keys. I did choose to enroll the Microsoft keys as well, to prevent any potential bricking due to 3rd party drivers from HP being signed with those keys.
After doing that, and rebooting(it did boot, powerLED, fanspin etc.), the laptop did not give any video output on the LCD or video connectors. I think I was able to get in BIOS and trigger the beeper by pressing ESC. So the BIOS was not corrupt but at least no video out.
EliteDesk Repair
I had this exact same situation happen to me (because then I did *not* include the MSFT keys) on a HP EliteDesk 800 G2 DM, which I managed to repair by desoldering the SPI ROM and replacing the BIOS region with UEFITool 0.28 with a fresh BIOS region extracted from an HP update executable- That is all I had to do.
Their behaviour was fully shared between the Elitebook and Elitedesk, no video, but able to get in BIOS and trigger beeping with Esc or F10.
My tools:
- CH341A (3.3V modification)
- EZP2023+
- UEFITool A78 (latest I think)
- UEFITool 0.28
Elitebook Repair
Because of this earlier success, I went straight ahead with this machine. Desoldered the ROM, dumped it and replaced the BIOS region, and resolder it.
Then it had the following behaviour:
Any help will be greatly appreciated.
If someone would be able to provide some expertise, I'd be very grateful.
BIOS Corruption - Cause
So I managed to corrupt my machine by installing linux and enrolling custom secure boot keys. I did choose to enroll the Microsoft keys as well, to prevent any potential bricking due to 3rd party drivers from HP being signed with those keys.
After doing that, and rebooting(it did boot, powerLED, fanspin etc.), the laptop did not give any video output on the LCD or video connectors. I think I was able to get in BIOS and trigger the beeper by pressing ESC. So the BIOS was not corrupt but at least no video out.
EliteDesk Repair
I had this exact same situation happen to me (because then I did *not* include the MSFT keys) on a HP EliteDesk 800 G2 DM, which I managed to repair by desoldering the SPI ROM and replacing the BIOS region with UEFITool 0.28 with a fresh BIOS region extracted from an HP update executable- That is all I had to do.
Their behaviour was fully shared between the Elitebook and Elitedesk, no video, but able to get in BIOS and trigger beeping with Esc or F10.
My tools:
- CH341A (3.3V modification)
- EZP2023+
- UEFITool A78 (latest I think)
- UEFITool 0.28
Elitebook Repair
Because of this earlier success, I went straight ahead with this machine. Desoldered the ROM, dumped it and replaced the BIOS region, and resolder it.
Then it had the following behaviour:
- When connecting power (battery or ext. power), the charging LED flashed white/amber (white/orange) for a few seconds.
- This would indicate, according to the 820 G4 Maintenance and Service Guide (page 70): "The embedded controller is recovering the boot block or DXE. Since it takes 10 sec. or so to load the DXE image and get video in the DXE case, this blink code is necessary. (SureStart)"
- Then it went off for a few seconds, and then the charging LED came back on solid amber/orange, either with or without battery present.
- But the machine would not start up, no power LED, no fan spin nothing.
- Removing the power, holding the power button, windows + B, or other button combinations etc. all did not work.
- When reconnecting the power, I experienced the same as step #2 & step #3.
- A lot more LEDs(I think WiFi, charging and power) came on, and stayed on.
- The Power LED came on when pressed, and after a few seconds the fan started spinning up to max speed
- Still no video.
Any help will be greatly appreciated.