AdrianMaule,

I don't recognize the 4-4-2 beep code, the two codes shown for the 4-4 series are shown below.  

4-4-1 Super I/O chip failure; faulty system board

4-4-4 Cache test failure; faulty processor 

Do you notice if the last beep is a longer one? If so then it may not be intended as a beep for the code, meaning the code would be the 4-4-1. What is the problem you are seeing with the system, a no POST?

Let me know.

Nope, very clearly, 4-4-2.  Yeah, there's no POST, just fans, no video output. 

We abandoned the server, taking the drives out and putting them in another 750, extracted the data, and abandoned the other 750 as well.  P4s just aren't worth the mucking about.  Thanks for your replies.

Take the 750 to it's minimum bootable hardware configuration. That is removing everything from the server but the following;

• • Processor: P4 3.0Ghz/800Mhz or Celeron 2.4/400Mhz
  • Memory configuration: 256mb installed in Slot 1-A
  • Power supplies: 1 @ 280W
  • Fans: 1 (Processor) 

    After that then power up and see if it powers. If so then individually start adding the removed devices back to see if you can identify the problem device.