Nintendo Game Boy Pocket

The Nintendo Game Boy Pocket is a revision to the original Nintendo Game Boy released in 1996, featuring a smaller body and a larger screen. To open a Game Boy Pocket, both a triwing and a phillips screwdriver are needed. To open a game cartridge, a Gamebit screwdriver is needed.

Gameboy Pocket MGB-LCPU-02 motherboard front

Gameboy Pocket MGB-LCPU-02 motherboard back

Problems and solutions

Problem	Solution
Nintendo logo corrupt without any cartridge inserted	Make sure the cartridge slot gold contacts are not mashed, otherwise it's probably the RAM chip being faulty. Removing it and booting will restore the nintendo logo to a solid bar, as it should be. If that's the case, it's safe to replace the RAM and that should likely fix it.
Cartridge not reading or crashing on startup	This is most likely an issue with the cartridge itself or the cartridge slot. Clean the slot or the cartridge contacts with isopropyl alcohol. If every single cartridge is doing this, it could very well be an issue with the cartridge slot. If the cartridge slot has been cleaned or replaced already, and you have another Game Boy (or compatible) system to check, then see if the console is deleting saved games. It could be the DC-DC converter board failing because of capacitor failure (see "Saved games are being deleted" below). If none of this checks out, then it's probably something to do with the RAM chip or CPU. Check for corrosion on the board, be mindful that sometimes it can be hiding underneath large components! (Yes, including the CPU) If it's all clean you can proceed with replacing the RAM chip. Should this not fix it, you can assume it being a CPU issue.
Saved games are being deleted	This could have 2 causes: either the coin battery inside the cartridge (providing energy to the SRAM chip) has died and needs to be replaced, or the C30 and/or C32 capacitors connected to DC-DC converter board are faulty or dead. To repair either: If the cartridge's internal battery is dead, the cartridge needs to be opened with a Gamebit screwdriver. Then, the battery needs to be removed and replaced with an equivalent coin battery (often times a CR2025). Any compatible battery will do if you keep the original battery leads in the cartridge. If your replacement battery has its leads attached to it already, you can solder them into the board. See video below for reference. If the C30 and/or C32 capacitors are dead, they need to be replaced with 330μF 6V and 100μF 6V capacitors respectively. Also see video below for reference. To determine which is the cause of the problem, you can try booting up a game, saving, and then turning the console off, and removing the cartridge. Try inserting the cartridge into another compatible system (if you have one, if not, try reinserting the game into the Gameboy Pocket), and see if the save file was created. If it wasn't, the cartridge needs to be opened and have its battery replaced. If the game did create a save file, it means the capacitors are faulty. Often times, faulty capacitors will cause the Nintendo logo at boot appear corrupted in the same manner when there's dirt in the cartridge slot. This is, however, unrelated, as it means the cartridge is unable to pull the 5 volts it needs to operate, and the console is attempting to pull battery power from the cartridge itself, causing the game to fail to boot and erasing the contents of SRAM in the process. This issue can also manifest in the logo showing up correctly, but then the console crashing to a white screen.
The console has no sound	Try checking if plugging headphones into the 3.5mm jack outputs audio. If it does, then the speaker needs to be replaced. If there is no sound in the headphones either, it means the C31 capacitor is dead. A 100μF 6V capacitor is needed to replace this. See videos below for reference.
Screen has a burn mark	If the screen has a large burn mark in the center, but still powers on and displays images (albeit discolored), the front polarizer of the display needs to be replaced. Refer to the video below. If the screen doesn't turn on at all, it needs to be completely replaced. Because there are no third-party replacement screens for the Game Boy Pocket (other than backlit mods), the display needs to be salvaged from a non-working console.

Identifying damaged components

Sometimes (not always), it's possible to detect if a capacitor needs replacement by looking at it. The capacitors in the board don't tend to swell enough to be recognizable to the naked eye, but it's still enough for a small crack in the paint to appear. See example:

Image corresponds to a Game Boy Color, but the principle is the same: the black portion (corresponding to the negative side of the capacitor) should be uniform like in C35 to the left, but it has a silvery crack across it, meaning the capacitor has swollen.

Repair videos

Troubleshooting audio problems and replacing C31 capacitor

{{#evt: service=youtube |id=https://www.youtube.com/watch?v=eEKxUix06mw }}

Replacing speaker

{{#evt: service=youtube |id=https://www.youtube.com/watch?v=jP69tCcu5OM }}

Replacing capacitors

{{#evt: service=youtube |id=https://www.youtube.com/watch?v=mkGXCPVE7NQ }}

Fixing burned screen

{{#evt: service=youtube |id=https://www.youtube.com/watch?v=vgVgu5Suw44 }}

Replacing game cartridge battery

{{#evt: service=youtube |id=https://www.youtube.com/watch?v=NyEXRXeuA5w }}

Replacement parts

Part	Store link
Cartridge Slot	Unavailable at this time
RAM	LH5164AN-10L