how to fix the bottom part of the screen which turns black

[bngyuh]

the bottom part of the lcd screen turns black where else everything is fine on top..and anything written at the bottom part shows in red

 

[ddpruitt]

More than likely the LCD itself is damaged. If moving the cables doesn't change anything you're going to have to replace the display.

 

[prit87]

remove the vga cable or dvi cables whatever you have and see in standby mode and check the black lines .
it may be a faulty GPU, faulty cable or simply a faulty monitor.