This kit comes with all the capacitors needed to fix your Game Gear power board, as well as the main IC that generates the voltages, plus all 3 power transistors. We have yet to come across a power board that has not been fully repaired with this kit.
3 power transistors (A, B and C)
Developed under the name "Project Mercury", the Game Gear was the primary competition to the Game Boy, the Atari Lynx and the TurboExpress. It shared much of its hardware with the Master System, and can play Master System games by use of an adapter. Sega positioned the Game Gear, which had a full-color backlit screen with a landscape format, as a technologically superior handheld to the Game Boy.
The Game Gear was notorious for bad capacitors, which means almost no Game Gears exist in the wild that work without repair.
If the normal capacitor replacement fix does not solve your problem, you likely have a bad power board. You can test the output voltage of the power board by supplying it with 9V and testing your output pins get 34V, 9V and 5V outputs. If not, this kit is for you.
To install, simply remove the old components and solder in these new components. Pay attention to the location of the dot on the main IC, and the polarity of the capacitors to ensure you install them the right way around.
For the transistors, the large one replaces the large transistor, and the two smaller ones that look identical are not. They come labelled in a bag A and B, and should be replaced by the correct A and B transistors shown in the image.
NOTE: On some power boards transistor B is located on the back of the board.