XO Temporary Backlight Cable Repair
If the small black tab of the connector has been broken off and fails to stay in place, the motherboard will need replacement. The connector will have to be replaced, a delicate soldering job difficult to do with a soldering iron.
Photo needed here, a closeup of the backlight connector
A temporary solution is to wind a small strip of paper several times, or cardboard. Jam a small piece of it into the connector (on top of the cable) to hold the flex cable in place. A piece of tape covering the connector provides additional stability.