If the screen just stays white, then it's likely a failed inverter board.
Or, could be a failed display, or even a logic board - that's where the video chip is located.
But, I would be most suspicious of the inverter board. Not too difficult to replace, if you can find a good part.
$25 or so for a part, found one here -
https://www.pchub.com/uph/laptop/43-24824-3558/Ambit-U04I054.01-LCD-Inverter.html