Oh well, you learn something everyday .... you can't pop your pre-upgraded RAM back into your Mac.
I upgraded the standard 512Mb X 2 that came with my iMac to 1GB X 2, that I bought from Crucial.com.
I just put the 512Mb X 2 back into the slots and my iMac wouldn't boot ... just a flashing power light on the bottom right.
There's my contingency plan blown out of the water ... I was going to put the original RAM back in the machine if and when it needed to go in for repair ....
It does make sense that once the machine starts utilising the 2GB RAM it just can't do operate in the new sense when it only finds 1GB installed.
I upgraded the standard 512Mb X 2 that came with my iMac to 1GB X 2, that I bought from Crucial.com.
I just put the 512Mb X 2 back into the slots and my iMac wouldn't boot ... just a flashing power light on the bottom right.
There's my contingency plan blown out of the water ... I was going to put the original RAM back in the machine if and when it needed to go in for repair ....
It does make sense that once the machine starts utilising the 2GB RAM it just can't do operate in the new sense when it only finds 1GB installed.