Since this is becoming an ever increasing problem, it gets its own sticky.
As the Virtual Boy gets older, things are bound to go wrong with it. One of these is the video display cables loosening.
The symptoms can vary greatly. From glitchy graphics to lines on the screen, and even reversed images. All of these are most likely caused by a similar problem.
Each LED displays is connected to the PCBs via a strip of cable which is glued to the display's contacts. Over time it appears that these cables can separate from the displays, causing the display problems.
The following are instructions for repairing the displays yourself:
* Visit this webpage: [url=http://www.virtual-boy.org/projectvb/projects/Dissect.htm]Dissecting the Virtual Boy[/url].
* You first have to open the Virtual Boy. It uses custom 'star' screws commonly found on earlier Nintendo consoles. While there are screwdrivers/bits out there, these are too short to reach the deep screws on the console. Some people have had luck melting hollowed out 'biro' pens onto the screws then letting them cool, leaving you with a screw-shaped pen. Others have cut out a flathead screwdriver (as viewed on the dissecting webpage), and finally [url=http://www.virtual-boy.org/projectvb/projects/SecurityBit.htm]Modifying a 'Security Bit'[/url]. to fit the deep screws.
* Once open, remove the display cable(s) from the display PCB, then follow them to the LED display(s). You'll have to remove the screws holding the mini PCBs.
* Reheating the glue: This can be done by many methods. DogP's webpage suggests using the oven. Once heated apply pressure to the cables to make sure they are firmly affixed. DogP also suggests using some sticky tape on them once they have cooled.
* If everything has gone OK, you should be able to reassemble the VB and test it by using the test screen (Left, B, Down, A, Up on the right D-Pad during the title screen of most games), or just playing through a game.
Hopefully this helps anyone with their bad displays. Feel free to ask on the forum if you have any more problems.
Finally, I recommend [url=http://www.virtual-boy.org/projectvb/projects/DisplayFix.htm]DogP's webpage on fixing the displays yourself[/url].