Checking Mactracker I find the following memory requirements
Earliest----PC-2700
Early 2004 to early 2005---PC-3200
Late 2005---PC2-4200
Assuming your memory matches these requirements and are of good quality they should work. Did you install them in pairs? I am including a link on The Powermac that should help you. Good luck
Checking Mactracker I find the following memory requirements
Earliest----PC-2700
Early 2004 to early 2005---PC-3200
Late 2005---PC2-4200
Assuming your memory matches these requirements and are of good quality they should work. Did you install them in pairs? I am including a link on The Powermac that should help you. Good luck