I had to poke around in a couple of fruit-flavoured G3 iMacs today, as neither was booting properly. The inside of the iMac is a pretty interesting place, so here's a quick detail of what I did should it be interesting to anyone else. Needless to say, if you're not comfortable pulling computers apart, working with mains equipment or near the potentially fatal voltages found in the Cathode Ray Tube [see below], don't try this.
The first thing to do was to prepare. I found the Service Manual on the web, which contains troubleshooting and take-apart information. This is not quite indispensable, but gives you a good idea of what to look for. Read the take-apart section before you start working, so that you don't have to keep stopping and looking back.
Place the iMac face down on an anti-static mat, taking all the usual anti-static precautions. On the bottom near the back is a single screw in a recessed handle. Unscrew this (it won't come out though), and give the handle a good hard tug to get inside the case.
The good news is that if you just want to access the logic board, memory or drives, you don't need to go anywhere near the CRT
That was the easy bit
Coming soon: PRAM battery replacements and software upgrades