How to check if a BIOS chip is damaged

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

Hello,

I have a HP Probook 640G, which Winbond W25Q128FV BIOS I bricked trying to bypass the admin password. I have flashed it with CH134A several times, with multiple versions and different programmers (CH134A, ASProgramer, Colibri, NeoProgramer…)

All I have got is all the lights of the laptop on when booting, blank screen and the “Caps Lock” and “Block Num” keys flashing 5 times. Searching the web I have found that this flashing lights mean a mainboard failure, and the only component I susppect to be damaged is the own BIOS.

The Datasheet can be found here:

WINBOND 25Q128FV

Is there any easy way to check if it is damaged? checking voltages, resistances, etc? Must be the MOBO with the AC connected to check it?..

Thanks in advance

2

Did you check the chip content after flashing? Dump content of the chip in a separate read and compare it to the file intended to flash?

What type of 640G?

Attach / post the file you used for flashing!

3

Thanks @lfb6

Yes, I always make a read of the flashed file to compare it with the original one. I am not at home right now, so this evening will upload the file.

It is Proboook 640 G2

4

These are 2 of the files I have used, the original a one moded

SMC_ORIGINAL.rar (3.6 MB)
GV_HP640-G2_OEM_Atualizado_unlocked.rar (7.3 MB)

5

You are aware that SMC_original.bin is just a bios region with empty padding instead of FD, GbE and ME?

image
image1634×402 21.5 KB

If you flashed SMC_original.bin with a programmer this is a 100% brick.

6

Thanks @lfb6 ,

As you can see with the attachements, I have flashed other bin files, with the same result.

I have checked pins 1 and 5 in this way, getting 3.3V, but I do not know what more to check

maxres2
maxres21280×720 55.6 KB

7

Well, you don’t seem to check what you flash. Repeated flashing of ‘something’ without knowing if the image is good ends quite often in confusion.

If the chip can be programmed and read out properly and was working OK before you began fiddling with it I wouldn’t suspect a defect chip.

Good luck!

8

Thanks @lfb6 , I a newbie with all related to BIOS, I recognize it. So I do not know how to go on from this point. I will tray to find other bin files.

9

By the way: Those notebooks came with to different ROM families- N76 and N87

Do you have the original dump of this machine?

10

Believed that if, but no :roll_eyes:

I got that dump before to begin the process from windows with the HP tools, a photo from BIOS with the data of the notebook. The dump, as you have seen, was corrupted and is the only one I have.

My BIOS is N76, but in HP the N76 you can download is 9MB in size, so I think is only THE part of the bios that you can update.

1700727491388
17007274913881920×1440 437 KB

11

Try that one- it’s stock bios with cleaned ME, the machine should boot, but machine specific information is missing, one would have to insert it afterwards.

SMC_ORIGINAL_kpl_eNV.zip (7.9 MB)

12

THANKS @lfb6 … I will check this evening.

13

THANKS; THANKS A LOT @lfb6 … It works kike a charm. Now I am fighting to introduce my datas, but that is another war.

:clap: :clap: :clap:

1 Like
14

Thanks for the feedback!

So it either was NVRAM or ME, most possibly NVRAM. Unfortunately NVRAM is where your machine specific data (and a possible password) are stored.

You might restore the machine specific data with HP tools (if you have) or you can do another dump of your NVRAM after having powered up the machine a few times, see what did get written automatically and maybe restore saome of the identity entries.

Dump of the NVRAM can be done either by programmer or by ME tools (for ME11) - commands for complete SPI / bios region / just NVRAM:

ftp(w(64)) -d spi.bin
ftp(w(64)) -bios -d biosreg.bin
ftp(w(64)) -A 0xB10000 -L 0x40000 -d NVRAM.bin

15

Thanks again @lfb6 . By now I have almost all the datas included. The own BIOS has an option to introduce them (at least by now, I boots in " Manufacture Programming Mode").

I think that the only one left is the “Optioon Byte”. I have it, but when I introduce the number I get “CRC error” I will check that all the others are correct.

16

Just googled " Manufacture Programming Mode" and came over this, possibly already known to you:
" Manufacture Programming Mode"

You did find the OA3 Windows code?

17

Thanks, I have seen videos like that. No, I have not found it. By now I am trying to introduce all the datas. Right now I am not at home. This afternoon will go on.

At least I am very happy to see it working thanks to you :slightly_smiling_face:

18

Hello @lfb6 ,

Only to say you that I have entered all my own datas in the BIOS and it si working perfectly. Tha only odd thing I have seen is taht the BIOS has changed my UUID (??), but it works without any error.

Thanks again

19

If everything works and Windows is still activated, I’ve nothing to add. Otherwise one would have to try restoring NVRAM partial / completely.

20

Thanks @lfb6 . I will check differents tutorials to see If it is neccessary or I will fall in the same situation again. By now all is working fine.

As i said, THANKS