Can I fix a broken Gameboy Colour?

I was scouring eBay the other day and came across a GameBoy Colour that wouldn't switch on. It may sound odd but I was so excited by this, more excited than if I had come across a reasonably priced working GameBoy.

I already have quite the GameBoy collection and I am not sure I could justify to Laura why I'd possibly need another. A broken one however might be a good enough of an excuse? Obviously not, but I love a challenge and pretending to be an electrical engineer is quite a hobby of mine, so I couldn't resist.

The operating table

In the above image you can see some of the tools I used during this operation.

The blue mat is a soldering mat, it is heat resistant so hopefully you won't burn your furniture when soldering! It also has magnetic compartments for you to store your components, super useful!

The blue screwdriver is a triwing screwdriver. Most Nintendo products cannot be opened without one of these, which is quite annoying but I guess it puts off people opening their devices maybe? Didn't work this time!

The orange screwdriver is just a bog standard phillips screwdriver. The Gameboy motherboard is attached to the front shell using phillips screws.

The blue device with a dial is called a multimeter and is used to measure voltage, resistance and current. One of my favourite features of this device is the continuity check where you can see if a component in a circuit can make a connection to another part. This is really useful for finding faulty connections.

There are a few additional tools I used which aren't in the above picture. The first is a soldering iron which is a tool used to replace or add additional components to a circuit permenantly with solder. Which is sort of like a conductive glue that melts under high temperatures. The iron is used to heat the solder and apply it to circuits.

Another tool I used as part of this operation was a heat gun. Its essentially a hair dryer that heats up to extremely high temperatures. Please don't use one as a hair dryer. It can also be used to light BBQs!

Step 1: Opening up the GameBoy

Using the triwing screwdriver I removed the back of the GameBoy to reveal the motherboard. The battery terminals look in good condition. If they were a turquoise blue colour it would suggest that the previous owner had left batteries in for long periods of time. As the batteries start to corrode, they begin to corrode the terminals which may cause the GameBoy to not get enough power to switch on.

At this point I actually missed one of the main reasons the GameBoy wouldn't start up, can you spot it?

Step 2: Checking the fuses

At the bottom of the motherboard, the GameBoy Colour has two fuses. A fuse is a simple electrical component which has a thin wire within it. If a large amount of current which exceeds the fuses capacity passes through the fuse, then the wire will melt and break the circuit. The purpose of the fuse is to protect more important and potentially expensive electrical components further down the circuit from power surges.

If either of these fuses was burnt out then it may explain why the GameBoy wouldn't switch on. To test the fuses I used my multimeters continuity setting to see if current could pass through the fuse and create a circuit. Both fuses seemed ok.

Step 3: Checking the on switch

The on switch seems a pretty obvious contender to check. The switch, when on allows current to pass from pin 3 (which is connected to the batteries) to pin C which is the rest of the GameBoy. All that is inside of the on switch is a small piece of metal that slides from pin 1 (in an off position) up to pin 3 and C. Pin 2 is unused. Sometimes the piece of metal within the on switch can get grubby and prevent continuity between pin 3 and pin C. The way to test this is to switch the GameBoy to an on position and use the multimeter to check for continuity between pin 3 and Pin C.

When I tested this there was no continuity and therefore the switch either needed cleaning or replacing.

I hadn't soldered anything yet, so rather than cleaning the on switch I temporarily soldered a wire to branch pin 3 and pin C to see if the GameBoy would now switch on as it was in a permenant on state.

Above is my dodgy soldering job 😅. The red wire is to connect to an external battery terminal as I wanted to test if the GameBoy would power on without going to the effort of putting it all back together again.

The GameBoy still didn't switch on!?

Step 4: Checking the power regulator

Throughout the GameBoys circuitry it doesn't just operate at the exact same voltage as the batteries. Certain parts of the circuit need much higher voltages to operate correctly (such as the LCD screen). The power regulator is responsible for stepping up the voltage. Below you can see the schematic for the power regulator (taken from wiki.console5.com)

Pin 1 of the power regulator is connected to Pin C of the on switch and is therefore our 3V input. Notice on the right hand side, pin 7 outputs 5V, pin 6 15V and pin 5 outputs 13.6V. If this chip is failing it might explain why the GameBoy doesn't boot up. I used the multimeters voltage option to check the output of the right hand pins and a minimal amount of voltage was coming from each. This chip is completely buggered.

When looking at the second image of the blog post we can now see why. Take a look at the GameBoys speaker and you'll see a small circular piece of metal that looks out of place on it. That was supposed to be attached to the power regulator..

At this point we have a solid idea of the main issue. We need a way to see if the GameBoy will power on with a working power regulator.

Step 5: Removing the faulty power regulator

First things first, I needed to remove this broken chip. To do that I used my trusty heat gun, every time I use this thing it usually ends in disaster so I was quite nervous..

I prepared the GameBoy for surgery, the tape is heat resistant and is meant to protect other components from the heat gun.

I managed to remove the power regulator but noticed that all the components on it had moved due to the heat causing the solder to melt. I couldn't possibly attempt this again when removing a working power regulator from a donor motherboard.

That wasn't my only problem, when researching online, I found that the only GameBoy colour power regulators available were ones compatible only with IPS screens. IPS screens are essentially backlit screens that people install on their GameBoy colours. These screens operate at much lower voltages and therefore the manufacturers of these regulators assume they're going to be used with IPS mods. Honestly I wasn't planning on installing an IPS mod on this GameBoy Colour because I'd already done one before on another GameBoy and the kit costs ~60 quid. I just wanted the original LCD screen to work..

Step 6: The plan..

I had a GameBoy colour with an IPS screen mod from a prior project which had a working power regulator.

What if I..

Bought a new power regulator that only works with IPS mods
Applied it to the broken GameBoy
Removed the IPS Mod from the GameBoy with the working power regulator and applied it to the broken GameBoy

I'd then have two working GameBoy motherboards, and therefore two working GameBoys?

Step 7: The test

The plan sounded foolproof, however first we needed to make sure that the broken GameBoy would actually work with a working power regulator and that there were no further faults.

I couldn't possibly risk removing the power regulator from another of my GameBoy colours as that would be a complete disaster so I had another idea.

What if I just soldered some wires to the pins of the working power regulator and connected them to the pins on the broken GameBoy motherboard? That would mean I could test the broken GameBoy without having to resorting to heat gunning any other components.

The soldering was tricky, but it actually worked!! For the first time, the broken GameBoy colour powered on!

Step 8: Wrapping up

I'd finally identified all the issues with this broken GameBoy. Now was time to install the fixes.

I bought a new on switch and just simply replaced the switch entirely rather than attempting to clean it up (the component cost ~£1 so seemed less hassle)

The physical switch itself was a lot smaller than the original but seemed to not cause any issues!

I soldered on the new power regulator to the faulty motherboard, not my best soldering work

I then moved the IPS screen mod over to the faulty GameBoy motherboard. This wasn't a lot of work and simply just needed a couple of wires soldered to the select, B and A buttons (the IPS mod uses these buttons to alter screen settings etc)

The moment of truth, testing both GameBoys. Both now seem to work a-ok!

So to answer the initial question, yes I can fix a broken GameBoy colour!

I really enjoyed this project and learnt a lot about some of the inner workings of the components found within a Gameboy colour alongside some new techniques to triage damaged circuits.

I couldn't however have managed to learn nor even fix a GameBoy without the references below!