Hi,

Ok, in a bit I'll open the iMac and see if there's a dead battery. (Even if it's fine, I'll probably replace it anyway.)

Now, you mentioned resetting the PMU. Let me remind you that I am quite a newbie at Macs. I mean, I have fixed problems that have occurred with my Macs in the past, but that was just because they all had to do with replacing parts or reinstalling OSes, both of which are easy.

So what is PMU? Or, to expand on that, once I physically replace the battery and put the Mac back together, what do I need to do?

Thanks,

-Apostrophe