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RWS

Registered member
Hi,

I am having problems with the following laptop:

Brand: HP
Model: Elitebook 645 G10
Motherboard model: DA0X9TMB8D1 REV: D

It is an AMD 7000 series CPU laptop.

The problem is this: computer has came with BIOS password and also Windows locked to a company domain. I have done what I would normally do in such case:

1. Desoldered BIOS chip
2. Put it into the programmer
3. Made two .bin backups of original bios
4. I found a fresh BIOS image on the internet
5. Write the new fresh BIOS image to the machine

After I have done this the machine would not boot. It starts automatically when power is plugged in then:

1. F5 key LED lights up Orange
2. Power LED flashes White/Orange
3. Machine turns on and off like this a few times
4. Finally the F5 key LED turns off and the Power LED stays white
5. If I press power button in such condition I get 7 flashes on the CapsLock LED
6. Laptop reacts to the power button: if I press it long enough the machine turns off but then turns ON automatically and the cycle repeats

Under such condition I can see voltages on the motherboard going up: 3.3v, 5v are ON all the time. For a second or two I do get 1.8v for RAM and one of the CPU power stages (the high resistance one) goes up to 0.8v. Later these voltages go down and only 3.3v and 5v remain ON.


I thought this was just a corrupted image I downloaded from the internet. So I written back the original image. After soldering the chip back to the laptop I still get the same issues as described above. Power light flashing white / orange, Caps Lock LED flashing 7 times. Same voltages on the board.

I have checked the BIOS chip few times and it is programming and verifying fine each time. The soldering is done right: chip is always soldered back correctly with all the pins making contact. No components has been blowed off the board with hot air. Soldering has been done very carefully. I do not think my original BIOS would be corrupted. It has been read on two different computers but using same programmer (I have made two copies).

What could be the problem? I have seen on another forum someone having simillar problems with G8 and repaired by flashing the EC ROM.

I have attached both images of BIOS and EC ROM.
 

Download list

BIOS_Original.rar
8.5 MB · Views: 25

EC_Original.rar
12.1 MB · Views: 26

Last edited:
Not much images are available online. I have extracted bios.bin from original HP package, flashed and same result. Could it be possible the EC Bios went corrupted to? Can you extract EC image from the HP package?
 
Not much images are available online. I have extracted bios.bin from original HP package, flashed and same result. Could it be possible the EC Bios went corrupted to? Can you extract EC image from the HP package?
check AMD chipset
 
OK so I am an absolute idiot. I do hot air soldering very often but turns out this time I made a mistake. I allowed the idea for this in my head and I started thinking I could knock a component off. I could not find a schematic or board view but I found HP YT channel where they are posting maintenance videos about their machines. There was a picture of the motherboard. On this picture ROM is installed in some sort of a socket unlike on my board where it is soldered but everything else is the same. I noticed I must have knocked off a resistor when desoldering the chip. This resistor has been connected to pin 1 of the ROM. I found that on the other side of the track the voltage goes up to 3.3V max so I decided to replace the resistor with a soldered bridge. After doing so on original BIOS picture laptop wakes up. Keyboard backlight turns ON, power LED turns ON, all the voltages on the board are present, CPU getting warm but no display backlight and no picture. After about 10 sec the machine restarts.

I guess the bridge is not enough and replacing that resistor is essential. There is no board view no schematic so I do not know the value of the resistor. I found schematics for other laptops with similar ROM and design with the resistor connected to pin 1. Normally these resistors are within 22 - 220 ohm. I will give it a go later today. Any other ideas on the resistor value? Thank you.
 

Download list

Capture.JPG
OK problem solved. Machine boots up. Could anyone be able to build a BIOS image without the password? Thank you
 
The BIOS post screen says "Protected by HP Wolf Security". Will patch surely remove the BIOS password and Microsoft autopilot?
 

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