Notes:
This method only works with a good backup of the original BIOS.
A programmer is required CH341A, better still T48 or RT809H
An original dump of the locked BIOS is required.
The BIOS chip is usually located near the RAM slot or the CPU.
Usually as an SPI 256 Mbit WSON-8 chip e.g. W25Q256XXX
Please do not confuse it with the Thunderbold chip near the USB-C port, this is not the BIOS chip.
I do not guarantee that it will work.
If everything has been processed correctly, please be sure to look at the chip soldering point to ensure that the chip is connected correctly.
If the power switch only lights up amber when you press it, it may be that the chip has no connection.
After I have programmed the unlock, I remove the CMOS battery, power supply and battery.
The restart will then take some time, please be patient.
The fan then runs at full speed. This is completely normal.
With this method it is necessary to re-enter the service tag.
This is very important for analyzing the 2nd, 3rd or 4th correct offset lines, as an example.
Correct scheme of bytes distribution: The 4th Byte is a random number 5th to 8th are 00 Bytes numbers.**
Offset(h) hex value:
000470a0: 00 FC AA 81 00 00 00 00
└──1.Byte └──2.Byte └──3.Byte └──4.Byte └──5.Byte └──6.Byte └──7.Byte └──8.Byte
Wrong scheme of byte distribution: The Bytes from 4th to 8th are random numbers or letters.
Offset(h) hex value:
001d5290: 00 FC AA 3F 81 3C A3 0C
└──1.Byte └──2.Byte └──3.Byte └──4.Byte └──5.Byte └──6.Byte └──7.Byte └──8.Byte
The search pattern is hex value 00FDAA and 00FCAA
This search pattern only appears to a very limited extent.
The who after 00FDAA is then changed to 00FD00
The who after 00FCAA is then changed 00FC00
One thing is very important: the offset lines must not be more than 4
It can also be just 3 or 2 less.
5 offset lines and further is too much and will no longer start.
In the HxD Editor program you can search like in my instructions with a little understanding and practice.
You should also be able to use a hex editor in this case. You shouldn't be discouraged if it doesn't work right away.
It was important to me to find the four correct offset lines.
1. This pattern is searched for 00FCAA and 00FDAA
This search pattern is unique and rarely found.
The AA after 00FCAA is replaced by 00FC00. Example: 00FCAA to 00FC00
The AA after 00FDAA is replaced by 00FD00. Example: 00FDAA to 00FD00
Open HxD Editor “open” the file that is to be edited.
Open search
Search for: “Hex values”
Search for: “00FDAA”
Search for: “00FCAA”
Search direction “all” to “OK”
Continue searching: F3 or SHIFT + F3
Change file 00FDAA to 00FD00 to Save it
Change file 00FCAA to 00FC00 to Save it
Only three or four offset lines need to be edited.
Don't edit too far the lines are close together.
