Microvision

However, very few cartridges, a small screen, and a lack of support from established home video game companies led to its demise in 1981.

[12][13] Those that are still in existence are susceptible to three main problems: "screen rot," ESD damage, and keypad destruction.

The liquid crystal spontaneously leaks and permanently darkens, resulting in a game unit that still plays but is unable to properly draw the screen.

[3] A major design problem on early units involves the fact that the microprocessor (which is inside the top of each cartridge) lacks ESD protection and is directly connected to the copper pins which normally connect the cartridge to the Microvision unit.

The low-voltage integrated circuit inside the cartridge is extremely ESD sensitive, and can be destroyed by an event of only a few dozen volts which cannot even be felt by the person, delivering a fatal shock to the game unit.

This phenomenon was described in detail by John Elder Robison (a former Milton Bradley engineer) in his book Look Me in the Eye; Robinson described the issue as having been a significant enough issue during the 1979 holiday season (with up to 60% of units being returned as defective) that it resulted in significant panic among Milton Bradley staff and required extensive modifications to both later Microvision units and Microvision factories (the former being of his own design) to better dispel stray static charges.

[14] The Microvision unit had a twelve-button keypad, with the switches buried under a thick layer of flexible plastic.

To align the user's fingers with the hidden buttons, the cartridges had cutouts in their bottom (over the keypad).

Screenshot of Block Buster, which came packaged with the Microvision
The uncovered LCD screen of a Microvision, showing screen damage
The PCB of a Sea Duel game cartridge, showing the TI3496 processor from the TMS1100 family