3 Intellistation M Pros with beep errors

[t140568]

None have HDs,

2 of the machines give a 3-3-3 beep code, the other a 3-3-2.
3-3-3 = No ram code, right? I can assure you I have two 2gb sticks in the machine. I tried configuring them differently, same code.

The machine that gives the 3-3-2, is it safe to assume it's a bad mobo (given that IBM's remedy to clear the error is to unplug, wait and restart)?

Could the processor be the issue? A friend gave it to me because it fit (physically), but I have no idea if it's the right processor for the board. According to IBM's site, this processor was never offered. Processor is a P4 @3.06ghz/1M/533/04A: 524 SL8ZZ L612A820

What should I do to get a working PC out of the three? or are they even worth the time?
Thanks!