vostro 1400 flicker screen at below of screen-st line of white green colour

[meganin]

hi,i am having vostro 1400 without nvidea graphics,actually a refurbished motherboard,installed windows-7 few moths bak,for few weeks i am seein a flicker line at below taskbar area (i hav changed the taskbar at top of the screen-still the flicker line is at below of the screen)..wat wud it be--is my video chip in mobo is gettin fried or somthing-pls help,thanks

 

[meganin]

line is not alwys present,only ocasionaly