Category: Toys

What the listing stated:

Very clean, but doesn’t turn on

EBay

Yep. It’s a Gameboy Colour to me, but as it was sold using the American spelling of “Color” then that’s what it will be addressed as, going forward.

I’ve been after a “Color” to add to my collection for a while now, but it had to fit my very strict quality requirements, in truth it just has to be faulty, and this particular example has met my conditions. I’ve paid £30.00GBP for this example and I’m happy with that, it’s a very fair price.

The good news seems to be that it is in a really good condition, it looks as if the battery door is missing, however they are freely available and this is not an issue should I require one.

These units are known to sustain power failures and the repairs are well documented. By now the unit is close to 30 years old and as time advances components start to fail, these include, but are not limited to:

• Power switch failure: either a complete failure that requires replacement or quite simply a simple clean to remove years of tarnish and environmental gunk.
• Fuse failure: there are two fuses F1&F2 that are known to fail, normally due to a short somewhere else on the circuit, but sometimes due to a power surge or incorrect addition of an incorrect power supply.
• Via failure, small through the board connectors that are known to suffer with corrosion, requiring intervention with the addition of small wires to bypass the issue.
• Capacitors – known to fail on a regular basis, it’s sometimes good housekeeping just to get these replaced as they are a contributing factor as to why other components such as the fuses also fail.
• Worst case scenario: major corrosion or main board component failure.

We’ll cross these bridges when and if we need to.

Here’s a little info about the Gameboy Color console:

The Game Boy Color (abbreviated as CGB or GBC) is an 8-bit handheld game console developed by Nintendo. It was released in Japan on October 21, 1998, and in international markets the following month. Compared with the original Game Boy, the Game Boy Color features a color TFT screen instead of monochrome, a CPU running at up to twice the speed, and four times as much memory. It is backward compatible with games developed for its predecessor. The Game Boy Color was released during the fifth generation of video game consoles and competed with Bandai’s Japan-only WonderSwan, SNK’s Neo Geo Pocket Color, and Sega’s North America-only Genesis Nomad.

The handheld is slightly thicker, taller and has a smaller screen than its immediate predecessor, the Game Boy Pocket, but is significantly smaller than the original Game Boy. As with its predecessors, the Game Boy Color has a custom 8-bit processor made by Sharp. The American English spelling of the system’s name, Game Boy Color, remains consistent throughout the world.

Wikipedia

So, for now, let’s not speculate on its quality and issues until it arrives, when we can then carry out a proper assessment of the unit that has been received.

Assessment:

The package has arrived. The battery lid is missing as kind of expected, I will get a replacement sometime, but for the moment I’ll probably print one out on the 3D printer, it’ll be a totally different colour as I don’t have a “Teal” coloured filament to use. The product label on the rear is also damaged but I can easily get one of these as a replacement, however it’s not essential and will only be of cosmetic appeal.

The front fascia is in a good condition with only a minor scratch on the screen, however there are a couple of dents and dinks on the body where it looks as if it’s been dropped or bashed at some point.

All ports, switches, buttons and sockets look ok and seem to be operating as such with no resistance or signs of stickiness.

Again, the casing is in general fit to use, and in no way causes any issues with its operation when working. It is purely a cosmetic issue that i can address when the unit is finally working.

I have installed two AA size batteries, switched the unit on and it is most definitely dead. Repeatedly flicking the switch does nothing at all, so it is a situation where the unit will have to be opened up and further investigated. The assessment has not thrown up any other issues not already highlighted in the sales documentation, so in general I am quite happy with the outcome at this stage. let’s get inside and see what we can find.

Oops. Wasn’t expecting that. I’ve removed the six “tri” screws and as soon as I’ve separated the two halves, an amount of what looks like battery corrosion “crap” has fallen out as well.

With the two halves separated, I then remove the screen ribbon cable, remove three more screws and the main board lifts out.

There’s some good news here. The contamination looks as if it has been completely isolated to within the battery area, there is no sign of any damage to the Vias, or any other components on the main board.

I have obtained the schematic diagram for this circuit board for checking continuity, and i’ve been able to confirm there are no issues with any contamination damaging any traces to the board. We’ve been very lucky here, dodged a bullet, to coin a phrase.

I have removed a set of battery contacts from the battery area, and replaced these with a new set that I have in my spares box. I could clean these, but it’s good to remove all items that were originally contaminated and very possibly contributory to the fault we have today.

I have also cleaned the front and rear of the main board with IPA just to ensure that if there was any issues with contaminants on the board, they’ve now been removed.

The switch has been tested electrically with a multimeter and this is working fine. The three capacitors have been looked over and seem to show no signs of wear or deterioration, they haven’t been properly tested though, so let’s now check fuses F1 & F2.

For reference: Fuse F2 protects the DC jack, whilst F1 protects the battery compartment. Using the continuity mode on the multimeter, a continuity through the fuse should present an audible buzz that let us know the fuse is complete and has not failed in any way.

I start on F2 and get a healthy buzz that tells me F2 is working fine. However fuse F1 is a different story, there is no continuity and there is no sound, I check again and can confirm that this fuse has blown, maybe this is a result of the contamination that was in the battery area?

I’ve now attached the bench power supply supplying a 3v input to clarify the fault.

Fuse F2 has a 3v supply on each side, however our suspect fuse F1 only has a 3v supply on one side confirming that this fuse has blown. Once this fuse has been replaced I can check the voltage supplies on the remainder of the board, especially on the DC-DC regulator board, that supplies varying voltages from 3v – 13.6v required around the main board. On the main board the voltage regulator can be recognised as U5.

A quick check for short circuits doesn’t show anything of concern, maybe when the fuse is replaced it may well open up some other issues, the fuses I will be using are “resettable” fuses. These fuses seem to be the standard now for these units. Most resettable fuses—known as Polymeric Positive Temperature Coefficient (PPTC) or polyswitches—reset automatically and do not have a physical reset button. Once the underlying overcurrent or fault condition is removed, you simply disconnect the power source to allow the fuse to cool down, then you switch on again, if the same issue occurs, there is an obvious issue present that needs investigation, as stated above, once the faulty fuse is replaced I will be able to check other areas on the mainboard for correct voltages.

Just for information the fuse that needs replacing is approximately 4mm in width. You can see the scale in this picture taken alongside a ruler.

Let’s get on with the repair.

Repair:

First off I’ve printed a replacement battery door cover. As stated earlier I don’t have any “Teal” filament so I’ve printed it out on a purple filament. For the purposes of practicality (holding the batteries in place) it will serve a purpose whilst carrying out the repairs.

I have a replacement fuse, this work will now have to take place under the microscope as it’s just so tiny, think grain of rice size and you will understand just how small this component is, and it’s amazing that a component so tiny can completely shut down a unit such as this.

The supplied fuse is even smaller than the one on the board. If the original was 4mm then this one is probably around 1-2mm it really is minute. Here’s a comparison of them side by side on the microscope base.

That said I’ve removed the old fuse, wicked away the old solder and applied some flux and a couple of new dabs of solder. Compared to these new fuses the solder looks massive, I can assure you it isn’t and is greatly magnified.

With the bench power supply providing 3v I’m able to use the multimeter to confirm that the fuses are both working, however there is another issue and I suspect it is something I discussed earlier, but omitted to heed my own advice, about good housekeeping. I’ll come to that in a second.

Power is getting around on the 3v rail and is not an issue. However at the Dc converter I’m not getting the 5v or 13.6v rail, so there is another issue. The new fuse has dropped out again, and this is good as it proves it works. I let it cool for 30 seconds and it is back up and working and I’m able to continue tracing the fault. The big capacitor C32 that sits beside the DC-DC converter appears to be carrying a short, it is probably this that has caused the fuse to previously fail.

And my good advice was to change these capacitors for good housekeeping purposes…..and I didn’t.

Guess what I will be doing next?

There are three Capacitors on the main board and below you can see what their primary functions are:

• C32 (Main Power / DC-DC Filter): 100µF, 6.3V (Filters the incoming voltage; if faulty, the system won’t boot or will repeatedly reset).
• C35 (LCD Display Filter): 22µF, 16V (Stabilises the voltage to the liquid crystal screen; if faulty, it results in a dim or washed-out image).
• C38 (Audio Amplifier / Sound): 100µF, 4V (Powers the speaker and headphone output; a failure here is the leading cause of whisper-quiet audio).

Ok. Fortunately I have plenty of capacitors in my spares box so I was able to replace the three capacitors with no issue.

This done I then decided, prior to any reassembly to see if the power was now being distributed as it should, and I’m pleased to say it is. We have the full range of voltages now coming out of the DC-DC converter.

Now let’s get the unit reassembled, cleaned and then get some tasty pics taken👍

Result:

To finish it off and whilst the 3D printer was still warm, I’ve printed a simple brightly coloured yellow display stand to show it off on.

After a good clean the unit is now in a perfectly good working order. The fault appears to have been the faulty capacitors and battery contamination all probably combining to make the power fuse fail, a perfect storm if you like. The fuse and three capacitors have now been replaced to breathe new life into this game console. Cosmetically it’s still tatty and would probably benefit from a new outer shell and some labelling, however it works and to be honest that is all that really matters.

I wonder how many of these items just get thrown away because they don’t work? This probably took me about three hours in total with diagnostics and repair. Another piece of retro history restored, now joining my original Gameboy classic as part of my collection.

It’s been a pleasing little project, enjoyable and educational and it’s always good to hear the familiar beeps when it springs back into action.

Another one saved from landfill.

Thanks for passing by, as always it’s very much appreciated.