So I have a G5 quad and it boots ok, then the fans start to get pretty loud (I don’t believe full speed but I would say faster than it should be, but then after a couple of minutes, it freezes up and goes to sleep (sometimes it just freezes on what ever screen your on). I checked the LCS and it sounds like fluid is running through it ok (It is a Delphi LCS but no leaks) but its hard to know for sure if fluid is running through ok without taking it out. I saw what appears to be the red #7 LED under the ram slot turned on for a very short time and then the G5 goes to sleep. I can still wake it from sleep but idk why it keeps doing this. I suspect that it is an overheating issue, but could it be that there is just air in the LCS system? I haven’t done the research on that yet. I used istat menus and it seems like cpu a is running much much hotter than cpu B (Its in Fahrenheit). The cpu temps seemed to start out around the same temp, but that 200 degree F was about 2 mins before it went to sleep again. Now idk if the MAC OS X favors cpu A first and then under heavier load uses cpu B, but those temps do seem like the culprit.