Think we're both in a similar boat with our consoles. Mine bricked after I uninstalled a bad ISO60 WAD file (error on install then uninstalled via WAD mgr). After I rebooted, the video will not come on so I too am stuck with a bad brick \NAND corrupt situation. Unless your Wii fell off the desk\stand (etc), its most likely a waste of time to open up the console to 'check' components unless you want to try to install a chip to 'see' if life comes back to your system.
On a side note, I have 2 local shops that install mod chips and guarentee or refund so I really have nothing to loose to take my 'paper weight' in to see what can happen. I fully suspect that I may have to invest in a new system however this time may do a hard mod, and still watch what I install\uninstall. If this fixes, I'm thinking will be good news for the community to hear.