LCD not functioning, Tested lcd, logic board connectors working.

I have a phone here, the Lcd display seemed to not be functioning.

I have tested the Lcd and it is functioning, I then tested the Logic board seperate from the phone figuring that is could be the fpc connector, except with the lcd in another phone, it is working and with the same logic board aswell. Now where im stuck is, They are both working although when installed on this frame, they don't function. I found the Volume and Headphone Cable to be torn, but would this somehow be affecting the lcd from working? there is nothing else visibly wrong within the phone that i can seem to find.

could it just be this cable?

Pleaaase help, thank you.