sega game gear screen problem

[Hexlo]

My sega game gear i bought has black horizontal line on the screen. i can hear the sound and see the game and dont know how to fix the black line problem. i have been looking around on the internet and i cant find any solutions! so i was hoping someone who reads this post can help.

[kendrick]

Welcome to GameSX. Game Gear screen problems are pretty well understood, but not easy to diagnose since you have a replace parts or check connections one at a time. Probably you need to use the search function on the board to see what others have come up with. Here's a master topic we like to reference just to get you started.

http://nfggames.com/forum2/index.php?topic=2753.0