I stripped off the stock enclosure and tried a half-dozen USB cables I had lying about but none of them seemed to work, so I can rule that out. I hear it spin up but the Wii U doesn't recognize that it's plugged in at all. Well looks like my old external drive might have fully given up the ghost. Long story short: Don't trust the Wii U's USB power. and I also bought a spare Wii U, just in case. I bought an external storage with it's own power cable. I'm not sure they'll do it again so I'm playing it safe. I called Nintendo to try and pay them to fix it and they actually ended up doing an out of warranty no charge repair/replace. I couldn't run certain games and the system itself would crash when I went into the data settings.
When I tried to fix it by copying the data to the Wii U internal storage, the internal storage became corrupted as well. The external storage messed up (perhaps leaving it plugged in for so long, external storage included, and not using it messed it up?). I had a problem with my Wii U about three months ago. The safe option will end up the most cost efficient because it won't brick your system. If you can find an external storage option that has it's own power cable then that's your safest bet.
The Wii U definitely has external storage problems because its weak USB power. So what’s the best option in 2019? Should I just go with another externally powered 3.5” drive, pre-fabbed, should I nab a 2.5” drive and a y-cable, should I build my own of the two options, or has something new popped up that I should look into instead? Ideally I’d be fine with a 250GB option, and I doubt I’d ever fill that. The current HDD is 1TB, and the Wii U OS says that 888GB is free, so I barely use even 10% of that now, and the smallest drive on the market is 1TB. Here’s the issue: Everything currently on the market is way overkill for what I need. I’m thinking it somehow enters a deep-sleep mode after enough inactivity that requires a hard reset, but I’m not sure. I’m using an old circa-2008 WD MyBook Studio, so it’s definitely getting up there in age, and it’s actually done this in the past. Most of my important game saves are on internal storage, so had things really gone wrong things wouldn’t have been terrible, but it’s still something I’d love to avoid. Thankfully unplugging the external drive from power and data and re-connecting it had it up and running just fine, but shit was nerve wracking there for a moment. So I booted up my Wii U tonight to play the updated Shovel Knight package and had a slight moment of panic when I realized my external hard drive hadn’t mounted at system boot.