I have an eMac, just over four years old. It has sometimes refused to power on (nothing at all happens when I press the on button). It happened once when the machine was new and I got it fixed under warranty. It happened a second time last summer and, following the instruction manual, I took out and then put back in extra memory I had recently bought, and that did the trick. Now, tonight, it once again won't turn on and taking out and putting back in the extra DIMM hasn't helped. Neither has pressing the reset button. The power cable is in, the wall outlet works, etc. (I should mention that both of the last two times the eMac refused to power on, it had been unplugged from the wall socket.) Any suggestions?