Screen flashes white turns off, and repeats

I bought a used ds online a while back with the intention of fixing it as it was in a very cheap price for a working one, as expected something was off, the top screen was shaking and had a few dead pixels, so I ordered a replacement, used a tutorial from here on how to do it and started working on it, during taking the top apart the back of the shell cracked, so I put it back together to see if it worked, it didn’t, it flashed the bottom screen once and turned off, after searching for the cause I learned that it’s caused by one of the screens not working or not being connected properly, so I disassembled it again, reconnected the ribbon cable and put it back together, after doing that, the problem seems to be the same, but in a loop but this time it made a sound with the speakers (if the speakers are disconnecter it doesn’t make the sound)

I assume it’s a different problem, because when I disconnect the top screen it goes back to flashing only once, I didn’t manage to find anyone having the same problem.

I know I messed up by apporaching the screen replacement very confidently, I would appreciate any suggestions on what to do, thank you for reading.