Also, if it is what i suspect to be the cbhc mod, he will not help with that because he strongly urged people to not use this mod, but maybe since you didn't do it yourself, maybe he will help.
About not being able to get the sync to work to get to the menu, maybe find a video of a wii u starting up with cbhc, so you can time out when the "autobooting CBHC" screen comes up, you may be able to time it correctly on your console, but literally its like this
1. Hold the sync button down on the console, turn on the console while holding the sync
2. keep holding sync firmly, until just after the white Wii U screen, once "autoboot CBHC" screen comes up, you release the sync, and then give it another firm tap
There is literally a second to press the sync at the right time, so it might be difficult to get it just right, its tough without the "autobooting CBHC" screen showing up.