By the way, this was not it. The behavior after changing this capacitor is exactly the same. Anyone has had this happen on his G3?
Upon further investigation I've found another thread on this forum that solves a very similar issue just by letting it plugged in for awhile before starting it...
Hi! I've got the exact same iMac Blueberry and the exact same problem. I've just disassembled mine and I've seen the 470uf 400v cap bulging. I'll try to replace it and see if it makes some difference.
By the way, be very careful when dissassembling because the beige frame is very, very...