Hello, which exact G5?
If you don't know the model, find the Serial# & use it on one of these sites, but don't post the Serial# here...
How to find the serial number of your Apple hardware product...
If you're sure the RAM is good, try the Hair Dryer trick...
No power light at all...
It can show on any G5, and even many other computers & electronic devices of the period.
And see this last one in particular...
Heat gun better...
You don't really have much of a history on this G5 computer you picked up, it could be anything. So I would start with replacing the new battery you ordered. Then try starting the computer with all the ram removed from the motherboard. You should hear one beep when you do. That beep is very important as it's a good indication that the motherboard is not faulty.
Not 100% but a good indication it is not.
Then add one ram stick only and try starting the computer. You have a bunch of different ram sticks. They all may not be what the manufacturer of the computer called for, the ones they recommend are for best performance, but they still may certainly work so try some of them if you don't get a start at first try.
Thanks for your replies. I was going to make a new post since my original description has changed slightly, but I'll try instead to just update here. Re status light: At first it was three flashes, then after I had opened the cabinet a couple times and checked the boards, it became one flash, i.e. on/off blinking, however now it is not blinking at all (steady on). I do not know why the status light changed. No LED lights were ever on in the cabinet. So the self diagnostics is no longer telling us anything. As for what the Powermac is doing: I get a chime on boot up, but screen remains black and Powermac revs like a vacuum cleaner after a few minutes. Originally (when the status light was flashing), I did not get a chime. I don't know if it matters, but I do notice that the status light on the monitor goes green for a second on boot up but then goes back to yellow and stays that way. Re battery: I changed the battery to a new one but it made no difference. This Powermac uses a 3.6v cylindrical lithium battery. Re model number: On the bottom of the Powermac it says Model No. A1047. Re removing memory boards. The seller suggested the same thing to me. I tried one set then the other set, but no change in computer behavior.
THe fans would be normal with no OS to control them, not even PRAM.
Can you count the beeps or flashes?
1 beep = no RAM installed
2 beeps = incompatible RAM types
3 beeps = no good banks
4 beeps = no good boot images in the boot ROM (and/or bad sys config block)
5 beeps = processor is not usable
In addition to the beeps, on some computers the power LED will flash a corresponding number of times plus one. The LED will repeat the sequence after approximately a 5-second pause. The tones are only played once.
Note: In this case, a flash is considered to be 1/4 second or 250 ms or greater in length.