lcd problem

Hi to all, I make a machine , a blood pump. I want it to show its output flow via a 16x2 lcd display. I used a parallel 16x2 lcd display and a pic 16f877a. I can write what I want but display disappears after 4-5 vibration...I cant understand what is happening. I turn off led backlight but result is same. Please help, is there anybody who have an idea?

what type of lcd are you using? Is it hd44780 compatible?

dear ckt boarder I solved my problem....I found problem in software

Thank you for to try to help

lcd interfacing is not a much issue .... gud u have done it urself /// )