Black screen, green LED on a previously working softmodded Wii

Helllo everyone, I have a Wii that has been softmodded for many years. It was on 4.2U when I purchased it and I used Bannerbomb to hack it. A couple of years later I updated the softmod to a version with better Gamecube game support (I think it was modmii). Everything worked fine and I could load and play GC games from the SD card with no problems. The last time I used it it worked perfectly.. probably about a year ago.

Well I got the urge to play some Super Mario Galaxy, so I turned on my Wii and was greeted with a black screen. The power LED is green, and when I power it on the light around the drive slot flashes once. And that's it. I had Priiloader installed, but holding the reset button while powering on does nothing. I tried this with and without the SD card, with my USB hard drive unplugged just to be sure. The first time I modded it I installed BootMii and did a NAND backup. I have the original NAND and Key backup files. But I can't get BootMii to load. Unfortunately, my Wii was too new to have the hash comparison bug in boot2, so I had to install BootMii as an IOS. I thought by copying the BootMii folder to the card it would automatically start BootMii on boot, but I think that only works when it is installing in boot2. The SD card I'm trying to use to start BootMii is an old non-SDHC card freshly formatted with SDFormatter, with the original Bootmii folder and backup files copied to the root.

Did my Wii just have a random hardware failure? Or is it really bricked? It's annoying, because I took all the precautions. Installed Priiloader, blocked disc and online updates, backed up my original NAND, saved it for all these years and now that I need it I can't access BootMii to restore it. Any suggestions? Thanks in advance!