So I got a Wii U off eBay, and it turns on fine, even from the Gamepad, but I can't get the gamepad to sync with the system (I wish I could just connect it physically, but that's not an option). When I open it up, what should I look for?
Call Nintendo support and see if the gamepad is actually dead or not. I'd then go ahead and open it up.
This is more or less a common problem with Wii U's. Another one of Nintendo's brilliant decisions that you can't physically connect the gamepad to the console.
Isn't there an option to sync a gamepad by pressing the sync button on the console 2 times? Did you try that? If not, then I suggest trying to reseat the wireless card which is the card in the upper left if memory serves correctly.
If what I read online is correct, the Wii U gamepad actually connects to the console via a modified Wi-Fi protocol instead of the usual RF transmitters and receivers. If this is true, well that explains a lot like how I can go further in my house with the official Xbox 360 Wireless controllers and official wireless headsets than the Wii U gamepad. I can only go about ~10-15 feet from the console before losing a solid connection when I can go double that with my Xbox 360 stuff.
What happens when you press the sync button, it may have broken.. The Tablet uses a daughter board for the wifi, it could be faulty or just loose.. I think it's only held in with mechanical retention.....
That is...odd, maybe it's because current cheap Bluetooth can't do video and game inputs well. However, I had my gamepad as close as literally on top of my console, so that shouldn't have been an issue. I did reseat it, but I haven't done the pressing the sync button twice. When I press the sync button on the console, it shows the pattern I need to press, then when I press it on the pad it lets me type in the pattern, but after I do that it won't connect. I reset the daughter board, and couldn't get any better results.
Oh you're in the setup. Well don't press it two times. The other suggestion I would make is reseating the built in Wifi card in the console if you can be assed to do it. If not, just send in the console and the controller to the big N.
I took it to a local place and they're going to fix it for $75, which is still $25 less than Nintendo was charging. Apparently there was water damage, huh.