My phone turns on, but my display won't display anything.

Title. I’ve tried opening the phone up and checking the cable between the motherboard and the display, nothing. I don’t know what’s wrong with my phone - I don’t know how to troubleshoot it.

Maybe, you, the community, can help isolate this issue and tell me what’s happening.

(When I’ve put my phone to charge, it would turn on - but it’d blink. After that, the phone wouldn’t display anything at all. Tried charging again, nothing.)

(When I’ve tried pushing in the cable from the display to the motherboard, the phone did turn on without the use of charging, but, it’d still blink - and now, it won’t turn on at all.)