Telectrix means the supply.
So, I googled 'Nintendo Wii U shutting itself down.'
Country Selector at Nintendo - https://nintendoservicecentre.co.uk/support/wii/my-wii-shuts-off-on-its-own
This points to either unlicenced accessories or a damaged AC adapter causing the shutdown. When you exchanged the unit, did you change the AC adapter? Perhaps not.
In any event, I think this is certianly not an electrical problem to any longer concern the good burgers of ElectriciansForums with.
Hope all gets sorted out in the end!
EDIT: Plus what Danny said.