Bricked Wii U from missed update

My Wii U has been safely stored in it’s original box with all parts and wires for the last 3-5 years. I took it out to check on something and the gamepad starts up normally but the system is stuck on splash screen (White with Wii U logo) on TV/Monitor. If I click on any option save a few on the pad the pad also has this splash screen issue. I asked around and it’s something to do with missing an update during the time it was away. It’s essentially bricked without the software Nintendo would have (they no longer service them) to fix it and I don’t know who to turn to or what to do to fix it.