I opened up my summer 2001 iMac G3, and did a little bit of dusting on the inside. Quite a bit of dust and little pieces of junk fell out, but it did not look like any thing that actually broke off of the computer. I would think that it was stuff that fell in when the previous owner opened up the computer. When I put it back together and powered it on, I was very dismayed to see how dark the screen had become. It is quite hard to see anything. The brightness is all the way up, and I turned it up and down just to be sure. I shut it down then powered it back up, but to no avail. Could I have damaged something in the computer? Can I fix this? Thanks!