Sorry trying not to come off like a jerk just simply giving you the facts to help to do your thing faster so you can do what you are doing faster correctly with what I know from personal experience. I own one of these for three years sold it a friend with 250 GIG HD and look every which way to make sure I was doing right. For dissembling a eMac is not the most favorite thing to do for those who own one or have had to work one. I am only working off what I see and really no major hardware info. I have now purchased a second one these machine and just upgraded it with a new 300 GIG HD and replaced the ram 1 GB and just installed a pioneer Super Drive. Then I replaced the back fan with a faster and quieter fan.

Firmware update are always good thing to just test to see if it will load into the machine if you do not know your hardware profile. Apple firmware updates for the hardware will either load or it will not because it dose look at hard profile info before installing. I am not trying to make you mad but trying to help you and give you what I find on my own time. If you look up earlier there is a person who quoted my comment and information trying show you that you need to make sure that this is set right, and meaning by check pinout means that every company has different place they have there cable select,slave,master settings in different places and sometimes rechecking this simple over looked thing can cause allot of headaches most the time it is what you are talking about. I hope that is not mean or hurt full. Just trying to help with makes a correct and fast installation that can be enjoyed. shocked :-X