Laptop screen pulsing

Can anyone help,
I have a compaq presaio cq61

the other day the screen went dark, could just see the screen in the background, scrolled through forums and decided that it could be the inverter.
Purchased and fitted a new one screen lights up fine but now is continuously pulsating. Does anyone have an idea on this, could it be the wrong inverter? or other problems.

Your help in this would be extremely appreciated.