2209WA,vertical and horizontal line problem

* 2209WA 22'', horizontal flickering and vertical static lines =
* CN-0H735H-72872-08K-1FDL
* A02
* Windows 7
* available outportVGA, DVI,HDMI
* usable port DVI
* Hi i have a dell 2209WA monitor which appears horizontal flickering lines and after a while dissapears (starting from the top, like erasing them or fix the problem?) and the monitor return to the normal operation. Recently started to appear vertical lines too, but not flickering, static, which also after a while also dissappear. When the monitor works properly, (without vertical or horizontal lines) if you look closely you can see very thin horizontal static lines, it looks like bad analysis. although from time to time it works perfectly! like new! I have run all the test and diagnosis from the user guide manual of the monitor, i have uninstall and reinstall the latest drivers and i also have an external monitor on my pc so the problem is on the monitor itself. Also i have use print screen to see if the lines appears on the photo but nothing. The warranty of the monitor has expired so i'm trying to fix it by myself. do you have any idea what may cause this kind of problem? is it a hardware problem like ipboard, lcd panel or destroyed cables?