Things You'll Need
Instructions
Turn the NES system upside down and unscrew the six screws using the Phillips-head screwdriver.
Turn the NES system right side up and carefully remove the top of the console by pulling it straight up.
Unscrew the large black RF shield and remove it by pulling it straight up off the console. You should now see a flat, black cartridge caddy.
Unscrew the eight screws holding the cartridge caddy to the console's mainboard. You should now be able to see the 72-pin connector.
Clean the metal connectors with the cloth and the rubbing alcohol to remove any grime or buildup. If the connectors are not bent or broken, you may reassemble the NES after cleaning.
Use a screwdriver to carefully reposition any bent connectors. If the connectors are too bent or damaged, you may need to replace the connector completely by pulling the connector out of the motherboard and inserting another in.
Reassemble your NES and test it using any NES cartridge. The NES should no longer display a blinking power light when playing.