Nintendo Game Boy Pocket

Nintendo put the Game Boy Pocket on sale in Japan on July 21, 1996. It is the 1989 Game Boy, made smaller. Nintendo's own product page gives 127.6 x 77.6 x 25.3 mm and about 150 g with batteries. It runs on two AAA cells, where the first Game Boy took four AA. The screen kept its size but changed character. Nintendo called it clearer and easier to see. The Centre for Computing History in Cambridge describes a black-and-white display in place of the original's green tint. It also responds faster, with less blur in motion. Every earlier Game Boy cartridge still worked. Linking to an original Game Boy needed a converter, because the Pocket's link port was smaller. Nintendo Life credits Gunpei Yokoi and his team with the design. It calls the Pocket his final product before he left Nintendo. The first Pockets had no power light. According to the Centre for Computing History, an LED for the battery level was added because buyers asked for it. Colors multiplied as well. Nintendo Japan lists eight. It notes that silver and gold were sold in America first, and only later added in Japan with a metallic finish and a plastic case. The surprising number is the battery life. Fewer, smaller cells meant less running time. Nintendo quoted about eight hours on new alkaline AAA cells, and the museum gives roughly ten. Nintendo Life puts both against the original Game Boy's longer stamina and calls it the price of the smaller frame. The Pocket plays black-and-white Game Boy cartridges only. Cartridges made for the Game Boy Color alone will not run on it.

Playing original Game Boy cartridges in a body that fits a jacket pocket. Every cartridge made for the 1989 Game Boy runs on it, according to Nintendo. A clearer picture than the first Game Boy. The screen is black and white rather than green, with less smearing when things move. Easy power. Two AAA cells, or a 3 V adapter in the DC jack. Headphones. The speaker is mono, but the 3.5 mm jack carries the stereo sound the hardware produces. A base for a screen upgrade. Retro Modding documents fitting a backlit replacement screen to the Pocket, with some shell work for the brightness control. Where it falls short: there is no backlight. You play by daylight or a lamp, as with the original. Battery life is shorter than the original Game Boy's. Nintendo quoted about eight hours on new alkaline cells. It will not run cartridges made only for the Game Boy Color. Link play with an original Game Boy needs a converter, because the Pocket's link port is smaller. The first units have no power light, so a flat battery shows only as a fading screen.

Fit two fresh AAA cells and match the polarity marks. Then roll the contrast wheel through its whole range, because at one end the screen goes blank. If it still shows nothing, take the cells out and look at the springs for white or green crust.

The DC jack has a switch inside that cuts the battery circuit when a plug goes in. A corroded jack can leave that circuit cut. Try both power sources and note which one fails.

Turn the contrast up until the screen fills dark. Missing rows or columns then show as light lines. Note whether they run up and down or side to side, and how many there are.

Turn the volume wheel up first. Then plug headphones in and pull them out a few times, because the jack has a switch that mutes the speaker. If the headphones play and the speaker does not, that switch is the suspect.

Slide the power switch on and off several times and listen. Both symptoms are linked to a dirty power switch.

Take the cartridge out and look into the slot and the cartridge edge for dirt. Reseat it firmly. Make sure it is not a Game Boy Color-only cartridge, which the Pocket cannot run.

That is not a fault on an early unit. The first Pockets had no LED, and Nintendo added one later.

Cells left inside leak and crust the terminals. iFixit's guide opens the shell with a Y1 tri-point screwdriver and six screws. It frees the shell-side terminal and cleans it with isopropyl alcohol and a toothbrush. Steel wool and metal polish deal with heavier crust. This is home work with care. Badly eaten terminals are replaced.

The switch causes crackling sound, fast battery drain and, on modified units, reboots when the cells run low. The repair resource gameboy.github.io says the effective fix is to take the switch apart and clean it. It warns that the Pocket's switch shield has a tricky latch. Where corrosion has gone too far, an aftermarket switch can be soldered in. That needs moderate soldering skill.

A bad jack can stop the console powering on, even from batteries. gameboy.github.io describes a continuity test across two pins of the jack. Poor continuity means corrosion. The jack is desoldered and cleaned, or replaced. This is soldering work.

Corrosion in the switch inside the headphone jack is a common cause of a silent speaker. It is tested and repaired the same way as the DC jack: continuity across the switch pins, then desolder and clean. ConsoleMods suggests cleaning the jack with a pipe cleaner and isopropyl alcohol first.

A Pocket that stays dead with good cells and clean contacts may have a blown fuse. gameboy.github.io notes that the board came in several revisions, some with one fuse and some with two. Replacing one is a small soldering job. Find out why it blew before powering on again.

Accounts differ, and the answer is less hopeful than on the first Game Boy. On that model, heat applied along the screen connector often brings vertical lines back. An iFixit expert says the soldering-iron fix does not carry over to the Pocket and a new screen is needed. A modder on the ModRetro forums suggests a very light heat gun instead. The post warns that the lower ribbon melts under an iron. No success is reported there. The usual end point is a replacement screen, original or backlit aftermarket.

gameboy.github.io reports that saves sometimes vanish on modified Pockets. Its explanation is a voltage sag from the original power converter at startup, which can make the console draw from the cartridge's own save battery. Back up saves before fitting a new screen or other mods.