Sounds to me like you're not driving the BP (back plate) pin.
All LCDs require square wave AC drive. The ON segments are driven
opposite polarity to BP, the OFF segments in phase. PERFECT square
waves are required or you can damage the display with electrochemistry
effects (I.E. Electrolysis of the crystal molecules).

Chris Pringle wrote:
>
> Hi Everyone,
> I'm trying to make a circuit with an LCD. When I power up the PIC, the LCD comes on with the numbers on the screen. But after a few seconds it starts to fade. How do I stop the LCD fading. Do I have to switch the segments on the LCD on and off rapidly and pull down all the LCD pins through a resistor? All help is appreciated.
>
> Regards
> Chris Pringle