Noticed a post by gMODZ on here (system modder in Toronto). Took it over to his store tonight, he pulled my chip out and tried a new one (very professional install btw) and the new chip worked. He then put the old chip back in to test with his wires and it didn't work. So basically had a working chip that ended up dying while in the Wii (verified to be a genuine Wiikey--had hologram too).
Not sure whether it was my install that caused the issue or whether the Wiikey was a dud (even though it had been working).
Moral of the story---don't do it yourself!! And if you're in Toronto get all your modding done with this guy. He did it while I waited (and I was able to watch the whole thing) and was totally professional. Here's the site if any other Torontonians are interested:
http://www.gmodz.ca/. He said he's going to be doing the 30-wire D2C chips as well so I would suggest going there if you've got one of these chips.
Thanks for all those that posted. Happy to have my Wii back...