The most common reason that leads to a white screen is the existence of an erroneous connection between the video cable and LCD display. Failure of picture data to reach the LCD and a lighted back light give the screen a white blank display.
A white screen on a computer can be caused by other issues as well. The problem might be the motherboard, specifically its graphics card, which may be damaged or in poor condition. A defective LCD screen is another possible culprit.
The simple remedy to this problem is to diagnose any connection faults by reconnecting the video cable to the LCD screen. Be sure to restart the computer because some models do not operate properly without a restart. If this doesn’t fix the issue, then the motherboard is probably what is causing the blank display. If fixing the integrated graphics card in the motherboard is impossible, the solution is to replace it. To ascertain if the motherboard is actually faulty, try using another LCD or external display and connecting to it using the current motherboard. A persisting white screen proves that the error is within the motherboard. If the test screen functions appropriately, then the problem is the screen.