bernd1-1@web.de wrote:
... "tl;dr Go!" ...
TL;DR is short for "Too Long; Didn't Read", sometimes used to place the most important message at the very top for limited capacity readers.
... "AFAICT" ...
"As Far As I Can Tell"
Should I use this tutorial, that applies to the ThinkPad X200 where I got a ThinkPad X220, for opening the housing and figuring out what screws to open in order to get access to the chip or is there one for the ThinkPad X220, too
The hardware is not identical but will probably be similar-ish. The official X220 Hardware Maintenance Manual by Lenovo is available here:
https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/0a60739_04.pdf
Chapter 8 on Page 67 is where disassembly starts, you eventually want to complete the first step of 1120 "Removal steps of system board" but quite possibly you don't actually need to perform every single step before even though the manual says so, in particular I doubt that you actually have to remove the LCD assembly.
It's also possible that you don't need to remove the system board from the case at all, to access the flash chip. It depends on which side of the system board it is mounted on and I unfortunately don't know. If you're lucky it's on the top side of the board and you only have to go through step 1090 to remove the keyboard bezel.
You may have to experiment to get to know your X220. It might take up to a full day but hang in there, it's a great learning experience.
Keep in mind that the maintenance manual will never mention the BIOS flash because Lenovo does not intend for anyone to do component level work on the system. Their technicians must only ever consider the system board as a whole, quite wasteful btw.
You can of course compare the maintenance manual both to the X200 instructions on the web page and to your actual hardware to figure out how much overlap there is, either beforehand or as you go.
Take all the blahblah about having to be trained and certified and whatnot with a grain of salt. It's your hardware, you can do what you want with it, and taking it apart is highly admirable!
Viel Erfolg and in case you get stuck you can always ask questions.
Kind regards
//Peter