Nintendo Entertainment System
Problems with the 10NES lockout chip frequently resulted in the console's most infamous problem: the blinking red power light, in which the system appears to turn itself on and off repeatedly because the 10NES would reset the console once per second. The lockout chip required constant communication with the chip in the game to work. Dirty, aging and bent connectors would often disrupt the communication, resulting in the blink effect. Alternatively, the console would turn on but only show a solid white, gray, or green screen. Users attempted to solve this problem by blowing air onto the cartridge connectors, inserting the cartridge just far enough to get the ZIF to lower, licking the edge connector, slapping the side of the system after inserting a cartridge, shifting the cartridge from side to side after insertion, pushing the ZIF up and down repeatedly, holding the ZIF down lower than it should have been, and cleaning the connectors with alcohol. These attempted solutions often became notable in their own right and are often remembered alongside the NES. Many of the most frequent attempts to fix this problem instead ran the risk of damaging the cartridge and/or system.[citation needed] In 1989, Nintendo released an official NES Cleaning Kit to help users clean malfunctioning cartridges and consoles.

Q: When did Nintendo release a cleaning kit?
1989