Hp Cpmpaq nx6110, wont start just dead ! !

Hi! this is my first question, im looking to see if anyone would have a reason as to why my Hp Cpmpaq nx6110 wont start (or do anything) When i plug in the AC the power light on the front flickers, however when i try to power up nothing atall happens not even the fan or any beebs ? anyones thoughts would be grateful!
Thanks in advance