P15 Gen 1, Error 2203 but B0 / C0 are okay. possibly GPU swap?

[EnderFFX]

Hello!
I bought a P15 Gen 1 as defective and without much hints to its history.
Was sold as "cannot start, weird stuff on screen".

So i bought a replacement GPU (2070 Super) and BOOM it worked immediatly, i got lucky.

Only that error 2203 every single time with beep loud enough to wake the kids is annoying.

I sincerly tried to read up and got a U One to work (3.5.40, that update tool will always say 3-5-40 is latest on cloud althiugh i ran it 3 times, it updated once from 3.5.30 to .40. Is that a problem? P15 Gen 1 is old anyways...)

I naively followed the only halfway good YT guide to solve 2203:

ERROR 2203 ALL LENOVO MODELS

Its very annoying (music and crack-speed) but i managed to go through it.
BUT it turns out C0 was correct for me already so i still deleted & rewrote but its all the same.
I would not know if B0 is correct, how can i learn that?

Nevertheless, i am now lost after trying the relatively simple things.

I assume some piece of Hardware is not as it is supposed to be and of course first guess would be the GPU as i KNOW its not the same (was a P1000 before i recall).

BUT not sure if the 2203 comes from that, the previous ownder maybe did *whatever* to it.
AHHH and i also changed / upgraded RAM and added a SSD (was diskless)

So in total i changed:
-GPU (2070 Super)
-RAM (wild mix of what i had, Hyninx & Crucial)
-SSD (some Toshiba 256 GB SSD)

Do you have any idea / hints how i can learn which mismatch causes 2203 and how to counter it?

So far "MUTE" helps a lot ;-)

Thank you for any idea or guidance!

Ender

[EnderFFX]

Okay, here it comes.
STILL would love to solve that error, but by sheer intuition i found a low-tech solution:

I realized that the boot stick with U1 dows not require me to press "ESC".
So i tool the smalles & oldest USB Boot stick i can spare, formated it again and then renamed the EFI file so it cannot be found anymore (and spawn the U1 tool).

Guess what: 2203 comes up and beeps but then continues to boot the OS.

Muhahaha

:-)

(Yes i know you guys found that 20 years before but for me its like a moon landing :-) )

Okay, now please still consider to help me out on the original 2203 problem...

Ender

[EnderFFX]

Sorry, not for spamming but to help others who are too dumb to really solve 2203:
The solution above together with this USB-C drive i managed to shop in town is great:


It sits at the back of my P15 G1 and is very subtle.
also i discovered Automute to auto mute my Thinkpad on every reboot or shutdown, so i never hear that nasty beep again:
Auto Mute for Windows - Free download and software reviews - CNET Download

These things together create a "i nearly solved it".
For me that not only means less annoyance but i can also again use WOL!

So: STILL appreciated if you pro guys can lead me to the real solution.

Ender