Any way to read part of screen that’s broken during Apple HardwareTest

So I’m working on this reclamation project for this 13” 2010 MacBook Air. About 1/4th of the screen is broken, so normally I have it hooked up to an external monitor, which works fine.

Problem started when I replaced the keyboard recently after it’s power key stopped working. I did the replacement fine, the keyboard now works, but the computer is ghastly laggish when it’s doing anything.

I burned Apple hardware test onto a bootable USB, and ran the diagnostic, but the error code that it spits out is half-blocked from the screen damage. Bc it’s in AHT, the external monitor doesn’t work, and I can’t move the window to where I can see the whole code. All I can make out is “4SNS/1/40...” and that’s all I can see.

Is there anyway to figure out what the rest of that code is? I can’t seem to select text so copy and paste doesn’t seem to be an option either.