The Game Gear is an 8-bit fourth generation handheld game console released by Sega on 6th October 1990 in Japan, in April 1991 throughout North America and Europe, and during 1992 in Australia. The Game Gear primarily competed with Nintendo's Game Boy, the Atari Lynx, and NEC's TurboExpress. The handheld shares much of its hardware with the Master System and is able to play its own titles as well as those of the Master System, the latter being made possible by the use of an adapter. Containing a full-colour backlit screen with a landscape format, Sega positioned the Game Gear as a technologically superior handheld to the Game Boy.
Console5 Game Gear capacitor lists and schematics.
McWill's Game Gear LCD Mod
Comparison tests conducted by RetroRGB
Available to purchase from DragonBox here.