If your moving the screen and it goes white 9 times out of ten its the cable or screen to remove the lid and check behind the screen and see if the cable is the cause also check and see if you get the same results on an external monitor
check the power brick Update (01/02/2016): if the power brick is red the your issue is the brick if the it is yellow then your brick is good replace the brick
Step 1: Shut down your mac Step 2: power on your mac (once chime starts hold down the alt/option key until you see the boot options menu). Step 3: boot into your installer partition Step 4: click on disk utility Step 5: you know the rest from there Update (12/30/2015): oops sorry didntread all of it take the hdd out of the a machine and reformat it on another machine buy an external hdd dock
Take the tablet apart and strip the board down to the Motherboard if you have solder experience take the soldering iron , and go on-line a buy a "flux Soldering pen" they are 3.99 on ebay and also get some desoldering braid replace the dc jack you might have a weak joint or a bent pin