I assume you have tried the BIOS reset procedure? I think it’s holding FN + S + V while the system is powered off.
Is this the same as what @Evv1L@mastodon.ml mentioned?
Also there is a reset button in the bottom of the laptop near ThinkEngine controller: Power off the laptop, disconnect both batteries and CMOS and hold reset button for a minute.
If yes I'm going to try it now and get back to you
EDIT: I tried the Fn + S + V but wasn't sure if I need to do it while batteries are disconnected, or if I needed to hold it for the full 1 minute, so I held it down for about 20 seconds with the battery plugged in. Didn't seem to fix it.
As for the BIOS, some stuff I read in forum posts etc leads me to think that the the check isn't actually in the BIOS but in the EC chip, so replacing the BIOS wouldn't do much. Is this truly the case, or does a replacement BIOS also circumvent the EC check? Many thanks for your help.
I think it might be for the older models, I'll check the manual for it.
I tried updating the BIOS but you need a battery with at least 25% charge plugged in as well as the AC adapter for it to let you even begin the update process (actually an amazing safety feature). Since mine has 0% I cant do that xD