- Could be the laser, could be the motor that rotats the disk. If you can hear the disk spin up to speed it is probably the laser. Both are fairly easy jobs, the guides on here are a big help.
- HDD usually stands for Hard Disk Drive. My wii doesn't have one, only the DVD drive. But I also have a wii that doesn't give sound or video, and wondered how hard it is to replace the relevant audio-video encoder chip, which is available on-line.
- It could be worth checking the TV settings in the wii menu.
I have a heat gun with lo (300 C) and hi (600 C) settings. I've fixed 2 PS3 YLOD (excellent IFIXIT guide for that, by the way) and have just tried to fix an XBOX using this guide. Within 2 minutes of starting , using the hi setting and keeping the gun moving , one of the dark areas around the small chips started to bubble. I haven't tested the result, yet, but suspect the worst....
I think the guide should be more informative and precise about the heat requirement.
Next time I'm going to follow the settings (lo) and timings the PS3 guide suggests.
Though the internals are quite different - especially the way the heatsink (fan unit) joins to the mobo, no card reader, no separate control board - following this guide as closely as I could seems to have fixed a YLOD on a CECHG03 PS3 - at least it has fired up and is now updating.