Pioneer VSX 920 and Wii: up-scaling

Hello

I have hooked up my wii onto my Pioneer receiver (VSX 920) that is supposed to upscale analog toward hdmi
So receiver hdmi output is hooked up to my TV, but I have no image....only sound

Who could tell me how I should set up the video parameters on the receiver (Converter / Resolution / Aspect)?
Anything else I should look for?

Thanks

OK, so I tried on the 2nd component input, and it works.....
So I have 2 options: there are some options set up wrong, preventing that input to work. Or it is simply dead, which is bad since I need 2 (Wii and PS2)
On top of it, that receiver is 2.5 years old but was almost never used.....So if I was to buy a new one, it won't be a Pioneer !!!

Do you know this receiver?
What should I check for?