PowerPC :: IMac G3 Not Powering Up

I bought an iMac G3 at an auction, it is the Indigo version with 400MHz G3 processor, 10GB HD, hope that's enough to work out which one. It will simply not boot up at all, when I first got it I switched it on and it done the Apple chime sound, then nothing, no power light at all. Now if I press the power button, no power light, no screen, nothing, although the screen sounds like it is coming on (the static sound and the degauss coil), no more chime or anything, as well as the CD drive sounds liek its searching for a disc, and the hard drive clicks a couple of times. I do not have an Apple keyboard or mouse, and am using a standard wireless USB keyboard and an optical wheel USB mouse. I don't know if it just needs OS9 on it (it says that on the sticker on the bottom) and if that is the only problem. I pressed the PMU reset button in the RAM flap while it was not connected to any power, and this hasn't done anything.