Dell 5420 - XMC 25RH256CXIQ Can't read bios

[jblow2210]

Hi All,

Looking for from help/guidance.

I have a CH341a (3.3v modified) trying to read bios from a Dell Latitude 5420 with a XMC 25RH256CXIQ bios chip.

I have read many articles in this forum including
https://www.badcaps.net/forum/showthread.php?p=1140467

but nothing seems to be working.

When connecting the clip to the chip, the ch341a indicates chip is not detected. The chip is on the board and I have disconnected power and the battery.

Any other thoughts on what I could try?

Thanks

[SMDFlea]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Hi All,

Looking for from help/guidance.

I have a CH341a (3.3v modified) trying to read bios from a Dell Latitude 5420 with a XMC 25RH256CXIQ bios chip.

I have read many articles in this forum including
https://www.badcaps.net/forum/showthread.php?p=1140467

but nothing seems to be working.

When connecting the clip to the chip, the ch341a indicates chip is not detected. The chip is on the board and I have disconnected power and the battery.

Any other thoughts on what I could try?

Thanks

The bios chip is a WSON8 package.What clip do you have,is it a SOP8 clip,if so it will not work,you will damage the chip.You can get a WSON8 pogo pin adapter on aliexpress,amazon,ebay

[jblow2210]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Thanks SMDFlea for the response, I will look into that.

[jblow2210]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

After getting my WSON8 probe, I was able to read the BIOS chip. One concern I have is that each time I read the BIOS and run the command "certutil -hashfile filename.bin MD5", I get a different checksum as a result. Does that indicate an issue?

My BIOS chip is a XMC 25RH256CXIQ PPE46700 01 2121U in a Dell 5420 with the motherboard info as:
Motherboard info:
GDF40 LA-K491P
Rev: 3.0(A02)
2021-04-28

Copyright 2020
Rev: A02
PWB:67X1G

In reading the BIOS chip, I used a CH341a programmer, V1.7 (with the voltage switch), a WSON8 probe and NeoProgrammer v2.2.0.10. Since it does not have the XMC BIOS chip in its DB, I selected the MX25L25635E chip as the base. Does that seem like it would work?

On the off chance this is not an issue, I have added the dump file from the first read of the BIOS. If someone could help me remove the admin password, it would be greatly appreciated.

Thanks

[hoaca388]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

After getting my WSON8 probe, I was able to read the BIOS chip. One concern I have is that each time I read the BIOS and run the command "certutil -hashfile filename.bin MD5", I get a different checksum as a result. Does that indicate an issue?

My BIOS chip is a XMC 25RH256CXIQ PPE46700 01 2121U in a Dell 5420 with the motherboard info as:
Motherboard info:
GDF40 LA-K491P
Rev: 3.0(A02)
2021-04-28

Copyright 2020
Rev: A02
PWB:67X1G

In reading the BIOS chip, I used a CH341a programmer, V1.7 (with the voltage switch), a WSON8 probe and NeoProgrammer v2.2.0.10. Since it does not have the XMC BIOS chip in its DB, I selected the MX25L25635E chip as the base. Does that seem like it would work?

On the off chance this is not an issue, I have added the dump file from the first read of the BIOS. If someone could help me remove the admin password, it would be greatly appreciated.

Thanks

Backup fault.

[jblow2210]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Thanks for the response. I'm not sure what "Backup Fault" is and how to correct it. If you could elaborate some on this, it would be much appreciated.

[hoaca388]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Thanks for the response. I'm not sure what "Backup Fault" is and how to correct it. If you could elaborate some on this, it would be much appreciated.

Your backup file is not good, the problem is still from your programmer, in general it gave out a junk file.

[jblow2210]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Here is a second attempt. Can the admin password be removed from this file?

[hardware1]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Here is a second attempt. Can the admin password be removed from this file?

Here's your Unlocked file.

[jblow2210]

Re: Dell 5420 - XMC 25RH256CXIQ Can't read bios

Thanks hardware1, much appreciate. I will give it a try,