Picked up a blueberry slot load G3 iMac the other day at a sale for a couple of quid and i'm having probs .

When i got it, it would start up (with the chimes) and you could hear hdd activity etc but it would sit at a blue/purple screen not doing anything. I couldn't get it to boot from a cd etc.

I've replaced the 1/2 AA pram battery (when i managed to find one!) and reset the pram but now i find i have another problem. I can startup and get the chimes but it now sits at a black screen, there is less hdd activity and it seems to have fluctuating power as the power led seems to pulse and i swear the hdd/cdrom seem to spin slower. Also, if you try and reset it, it won't restart properly, you have to turn the power off at the plug and back on again to get the chimes again.

I know i should skip it but can it be fixed?.