A while ago I bought a commodore 64 at a expo. I got back home to play it. It didn't come with anything for the tv so I used the NES rf and even a Sega Genesis av plug but i had the power supply. The first few times the C64's led light came on (Obviously to indicate it was on) but there was no picture or sound at ALL. I left for a while and later I went to try it again this time it didn't even power on at all!

I've done a bit of research, I heard this could mean a burnt fuse, I opened the c64 to check out the fuse but it didn't looked to me like it was burned (but I might not know for sure what a burnt fuse would be like) and I'm not sure about the ram either.

So from this story, what problem is this? Is it the C64 or PSU (or maybe both) that are broken? What do I need to get to fix this?