When a Wii U is stuck on the White Screen with the Wii U logo, there are a few ways to try to fix it. The first is to move your Wii U Gamepad reaaaaaally far away from the console, and then power it on when you are sure it wont be able to connect, and see if it starts. The second is to power off the Wii U and bring your Wii U Gamepad back into range, so you can use your Wii U GamePad, Wii Remote, or Wii U Pro Controller, to power on the Wii U again. Press/Hold B when the White Screen with the Wii U logo shows up, it may load into vWii mode, and from there you can exit to the Wii U Menu. The final option is the most difficult, make a hardware dump of the current state of your eMMC user data, and Wii U NAND. And try to manually repair the dumps on a PC. Here are some images from WiiUBrew, good luck! eMMC: NAND:

Well, it's an Apple device. There are lots of things it could be, the abysmal 1GHz CPU definitely doesn't help, even for 2011 that is shockingly slow. The RAM is pretty slow at 1333MHz, but that should only be an issue during loading screens. The biggest factor here, besides being made by Apple, is this computer does not have a graphics card, and relies on the CPUs internal video processor to produce the most basic rendering abilities. Like showing the desktop and application windows, and some basic 3D display. Trying to game on embedded graphics is extremely painful, either play older games, 1998-2003 era 3D games should run at almost full speed on this machine, or see if Apple sells a dongle that lets you plug in an external graphics card. If you have the money, build a gaming rig for games, and just use this laptop for what it was intended for, office programs.

This is a dead question. But it's just a connection issue during an update and can be ignored. You don't need to update these days, most of the updates just disable existing capabilities.

Doesn't apply to my 7502 model.

Only remove the ribbon cable from the centre of the two ports.

Doesn't apply to my 7502 model.

Skip to next step.

Doesn't apply to my 7502 model.

Only remove the two 14mm screws.

Please don't blow in it.

Use compressed air, or clean the pins with 90+% isopropyl alcohol.