Game Boy Common Issues

All of these issues are covered in the relevant console page (most with more info) but this is just a quick document to detail the most common issues.

Game Pak Problems

Bootleg spotting: Check out this visual guide or even the /r/gameverifying wiki

Common problems

  • Power LED flickers, low battery light comes on early or intermittently, or the console randomly resets are all issues caused by a dirty or faulty power switch. Dirty or damaged switches can usually be fixed by cleaning out the switch. The most effective method to clean the power switch is to disassemble the switch and ensure everything is clean all the oxidation and buildup from the inside-out. The far less effective method to clean the switch is to spray contact cleaner or isopropyl alcohol inside the switch and simply work the switch back and forth. Make sure to let the switch dry out before turning it back on. Opening the switch is the most reliable and best long term solution. Other methods may still help, but should be considered a temporary fix. AGBs exhibit a flickering lower power LED and are the simplest to clean. Video CGBs and MGBs share a similar physical switch body and are opened the same way. Cleaning the power switch is the same method as AGB. Video

  • Game Boy won’t power on

    • On an unmodded console, the most common issue is a dirty or damaged power switch and can usually be fixed by cleaning out the switch. See above.

    • Blown fuses are a bit harder to fix simply because of the tiny soldering required. To test your fuse, a multimeter is usually needed. Simply measuring continuity across the fuse will tell you if the fuse has blown. Continuity shows power is flowing and the fuse is good. No continuity means the fuse has blown and opened circuit. Most Game Boys have two fuses, usually marked “F1” and “F2” on the main boards. Usually one fuse is connected to the battery terminals and the other fuse connected to the external power input, ie charging port in AGS and OXY or DC jack on CGB and MGB. Note, fuses are safety devices and a blown fuse is cause for further investigation and diagnostics. Please see this (WIP) list of Game Boy components to find the proper replacement fuse.

    • Damaged DC power jack in a Game Boy Pocket or Game Boy Color system can make the console appear dead. A simple USB to DC power adapter can help diagnose this issue. Similarly to the headphone jack, a physical switch exists in the DC jack that disconnects the battery terminals from the system when on DC power. Contacts within the DC jack may corrode from moisture and open the physical switch permanently. Careful cleaning can help, but with the center pin in the way, thorough cleaning may be difficult. Limited new and used DC jacks are available through eBay and AliExpress. For diagnostics, pin 2 and 3 as labeled on the console may be bridged. This should not be a permanent fix without fully removing the DC jack. Applying power to batteries with a DC jack inserted is dangerous. Alkaline batteries can explode.

    • Bad battery or battery connector in some models can cause issues. In models that came with rechargeable batteries (AGS and OXY), the battery may need replacement. AGS OXY On alkaline models, the connectors can get dirty or completely corroded. In cases of mild dirt or corrosion, a simple clean with a cotton swap and isopropyl will resolve the issue. In heavier cases of corrosion without physical damage, distilled vinegar and a cotton swab may be used to clean away all the corrosion. Terminals can be desoldered from the console and removed from the case shell to be soaked in vinegar for more severe corrosion. When vinegar is used, isopropyl should be used to wash away the vinegar as it is corrosive and will damage the board. In extreme cases of corrosion and battery leakage, the terminals will be corroded through and require replacement. DMG MGB MGL/CGB AGB

  • Common audio issues are caused by a few possibilities.

    • Fuzz or static when using headphones is especially noticeable when twisting the plug in the jack. It’s a pretty rare problem but generally easy to fix. Usually the headphone jack becomes dirty or corroded from moisture. Contact cleaners such as CRC/QD Contact Cleaner or DeoxIT can help clean out the port. For heavier cases, applying the contact cleaner to a cotton swap or pipe cleaner and thoroughly clean out the headphone jack. If corrosion is too severe, it may cause speaker issues as well.
    • The headphone jack is dirty or bad: Every Game Boy headphone jack has a physical switch that is actuated by inserting headphones. When this switch is open circuit, the Game Boy switches the internal speaker off. Corrosion or physical damage can cause the physical switch to be always open, meaning the console never switches the speaker on. Clean the headphone jack as thoroughly as possible. If a replacement is required, these parts are custom for Game Boys and will have to be sourced from donor consoles. There are very limited new-old-stock parts available. DMG AGB/CGB/MGB share the same port. NOS parts were once available, but are no longer for sale. This is a unique part due to the footprint and internal switch.
    • The speaker itself may be bad You can test this by desoldering the speaker and measuring the resistance across the contacts with a multimeter. You should get 8 ohms on a good speaker. Anything else (or open circuit) means a bad speaker. Speakers can be replaced as there are OEM-fit aftermarket replacemnents. However, speakers that go bad are usually a sign that the capacitors should be changed. BennVenn explains it, and while it is specific to the CGB, the concept still applies to other consoles. DMG MGB/CGB AGB
    • Dirty volume wheels can also be the cause of low volume or fuzzy/crackling sound. The wheel cannot be disassembled for cleaning. Cleaning involves spraying contact cleaner such as CRC/QD Contact Cleaner or DeoxIT and working the potentiometer through its full range multiple times to wash out contaminants. For fully corroded volume wheels, replacement is the only option. New-old-stock replacements are available, but limited. The only reliable source is from a working console. Schematics for all systems are available, and verifying the value of the potentiometer is possible.