Imac starts with a black screen and flashing white light on console

Question

I have a 24" imac, it is white and it is from the first year they used the intel chip. When I power it up I get a black blank screen and then the white light on the lower right side of the console flashes on and off. I hear the disk drive spin (I put the 10.4 install disk in ) and it does nothing. How do I get the disk out. I even tried holding down the mouse button at start up and that doesn't work.
I tried to remedy this myself by resetting pram. I have taken out memory and put it back in. I have been able to get it running twice before by taking out memory and putting it back in but it only worked for a little while and then I turned it off and went to turn it back on and same problem again. Is this a logic board problem or something else. I think I read if it was the logic board the disk drive wouldn't work but I hear it spinning.
Can anyone help me?

Answer 1

Hi MacGruff69
That has all the classic signs of unseated, improperly seated or bad RAM.
Laying the iMac face down on a soft towel and reseat the module(s) by pressing real hard on each one with both thumbs, then closing the ejector clips and replacing the cover.
http://support.apple.com/kb/HT1432
Them if the iMac still has the same symptoms, try one module at a time or replace the module(s) with new one(s).
http://eshop.macsales.com/shop/apple/memory/iMac/IntelCore_2Duo
Dennis