DMA Registers Problem

[noob]

Just changed the heatsink from stock to the Ninja the specs as follows:-

- Abit Fatal1ty AA8XE Motherboard
- Intel Pentium 4 660 "LGA775 Prescott" 3.6GHz

On the motherboard it's displaying "3.9" on the POST code display. In the manual that means - Test DMA Registers

I have really no idea what that means and wonder if anyone could help. Also, there's no display on the monitor, check signal.

Thanks