BW screen (Variant 9) not working (any more)

[Elefantenpogo]

Hello everyone,
I just resumed working on a GBZ build and stumbled upon some issues with my screen. It uses the BW board in Variant 9 and I did the 5V hack from the wiki. I started the build several years ago and postponed it at that point (for several reasons) and back then the screen worked (I even found pictures of it working), but when I tested it again today, it refused to turn on. I checked all connections, resoldered every joint, used different Pi's to connect it to (both of them worked just fine when I plugged them into a monitor via micro HDMI) but nothing worked. I checked voltage between the two pads I marked in the image below and it's about 5V, so the power shouldn't be an issue. The only thing I found was a little crack on the ribbon cable (see second image), but I don't know how to check that.

What do you think: may it be the ribbon cable (which would mean the end for the screen at this point) or may it be something I could fix by myself?