Yeah, you should be able to use that keyboard. I doubt that's your problem.
After six years, I'd reseat everything including memory and video card. I'd unplug and replug everything not already covered in your PSU exchange. Do you recall exactly what problems you were having before the machine was stored? Is this still the original hard drive? Do you have optical media to try to boot from?
To get more specific advice, give some more details about your system. Which model Power Macintosh are we discussing? From what you've written, it appears that you have an early model G5?
Thank you Swampus, jeff and kaz-k for your replies.
In reference to the question at hand, Yes I wrote down the information on the equivalence on the windows/mac keyboards and now I can try to boot my G5 (power mac 1.8 pci-x Dual processors, NANYA 256MB DDR-400MHZ-CL3 PC3200 in the top (upper) bank slot #1 and the same stick with 256MB DDR-400MHZ-CL3 PC3200 in the bottom (lower) bank slot #1 which that would be 512 MB total, for that pair, Also have ELIXIR 512MB DDR-400MHZ-CL3 PC3200 in the top (upper) bank slot #2 and the same stick with 512MB DDR-400MHZ-CL3 PC3200 in the bottom (lower) bank slot #2 which that would be 1024 MB total in that pair. Grand total of 4 sticks = 1536 total MB of Memory. I still have 4 empty slots for more memory, Slots #3 & #4 in both upper and lower are empty. So I have a total of 8 slots all together but 4 that are in use. I still have the same standard HD (160)GB in the (upper) (A) & in the (lower) (B) there is a 2nd HD with 80 GB, I remember I have on the (upper) (A) HD the (os) operating system running the X 10.2.7, and am not sure what is in the (lower) (B) Hard drive, Also have the dvd drive thats hooked up. The beg date is (11/2003) discontinued date is (6/2004), Apple Model #(A1047), and the E.M.C. (1969) APPLE Order # is (M9393LL/A) The Serial # (XB4050N4QUY). I remember the reason I had put it away in the closet was that the fans where excelerating at a high rate of speed and I did not want to risk any damage of overheating or anything, So I shut her down and tried to start her up again 6 years later, The power supply went out and so I have a new one installed and the fans are still doing the same thing after 5 min. start to sound like a Jet liner coming in for a landing.
I also have the signs of the memory uncompadablility, By the LED start buttom flashing (3) three times pausing 5 seconds in between each pause. So all I am seeing is a black screen on the monitor, I tried to boot it up with a friends OS 10.3 (1 OF 2) Disc. The screen came up with a question mark I-con and ask me if I wanted to load this os or keep the original os to start up with and I figured I would use the os that is on the computer because if I had use this os.(meaning the one that is on the cd that I had boot it up with) if so I woyld lose all information on the old or exsisting os that is on the computer, So I picked the one that is on the computer and tried to start the computer again and all I can get up is the speed of the fans but nothing else same 3 flashes of led start button and a black screen. that where I am at right now just trying to figure all this out maybe I have given all the info. possiblefor anybody out there that can point me in the right direction with Ideas or input to help would be highly apprec. Thanks again Swampus and jeff & kaz-k for your help.