Also... please before you even think about booting it into OSX again, reinstall OS9 on the hard disk, and obtain a copy of the latest iMac G3 firmware, I beleive 4.1.9 but do your research. I beleive I make mention of the specific version on my blog somewhere but it's probably as easy to google it.
iMac's booted into Jaguar, Panther or Tiger with out of date firmware will invariably suffer video degradation or in some cases nothing will display on the screen. If left, it can cause permanant damage to video hardware. The problem is, by the time you get the message about the out of date firmware, the goose has already begun to cook. THis is a particularly bad state of affairs withthe 350mhz model as you cannot plug in an external monitor to install the new firmware which will usually rectify the issue, making it a very big PITA to fix.
iMac's booted into Jaguar, Panther or Tiger with out of date firmware will invariably suffer video degradation or in some cases nothing will display on the screen. If left, it can cause permanant damage to video hardware. The problem is, by the time you get the message about the out of date firmware, the goose has already begun to cook. THis is a particularly bad state of affairs withthe 350mhz model as you cannot plug in an external monitor to install the new firmware which will usually rectify the issue, making it a very big PITA to fix.