When to attempt this fix It's a good idea to clean all your games and systems regularly as preventive maintenance, even if you're not experiencing problems. But if you are having trouble, cleaning will clear up the following symptoms:

1. Blank screens 2. Scrambled game graphics 3. Games that crash in the middle of play 4. On CD-based systems, games that won't boot up

What you'll need

1. Q-Tips 2. Windex or a solution of 25% isopropyl alcohol, 75% water 3. For cartridge systems, a cleaning cartridge (if one is not available, see the directions for hand-cleaning below)

What to do To clean a cartridge:

1. Dip a Q-Tip in the cleaning solution and rub firmly across the metal contacts on the dirty cartridge. Repeat until the Q-Tip comes out clean. 2. Use a dry Q-Tip to wipe off the excess solution. 3. Once the game is dry, plug it in to test it. You may want to remove and reinsert the game a couple times more to make sure the contacts are completely clean. 4. If the cartridge is completely clean and it still won't work, your system may need cleaning. See below.

To clean a cartridge system:

1. Apply solution to the appropriate cleaning device for your system. If you don't have one you can use a game. 2. Insert the cleaner into cartridge port, remove, and reinsert repeatedly. 3. Wipe dirt from the cleaner and repeat above steps until the device comes out clean. 4. Allow the system a few minutes to dry, then test with a clean cartridge. 5. If the system still won't work the contacts may need a more thorough cleaning or may be bent out of shape. See below.

To clean a cartridge system by hand: These instructions are intended for the older model NES but can be adapted to other systems. Genesis and SNES systems can be cleaned right through the cartridge port.

1. Remove the screws on the underside of the system. 2. Turn the system over and lift off the plastic top. 3. Remove the screws holding down the metal RF shield and remove the shield. 4. Remove the screws holding down the black plastic cartridge holder. Note how the small plastic tab on the front of the holder slides underneath the motherboard. Slide the holder forward and remove (it's all right if the motherboard bends slightly). 5. Lift the back of the motherboard up and pull off the set of contacts in the black plastic housing. (They will resist a bit but just rock them back and forth to slide them off.) 6. Dip a toothbrush (preferably not yours; use a loved one's) in the cleaning solution and scrub contacts off. 7. Rinse contacts off with water and allow to dry. 8. Lift up the back of the motherboard and slide the contacts back into place. 9. Lift up the front of the motherboard and slide the cartridge holder onto the contacts. Be sure the tab on the front of the holder clips underneath the motherboard. 10. Reattach the cartridge holder's screws. (The long ones go in the second set of holes from the back.) 11. Plug in the system and test with clean cartridges. (It's perfectly safe to do so with the top off.) 12. If the games still won't work, the system contacts may be bent out of shape. Greg Lambert has written an article on fixing them, available at http://www.classicgaming.com/features/articles/nesrepair/. Replacements can also be taken from another defective system or purchased from some electronics dealers. Try MCM Electronics for starters. 13. If the system is working properly, replace the cover (you can leave the RF shield off if you like; I won't tell the FCC) and reattach the screws on the bottom.

To clean a CD: 1. Apply cleaning solution to soft cloth. 2. Wipe the CD with strokes starting at the center and going straight to the outer edge. Do not use circular strokes. 3. Insert the CD in the system to test.