One of my work colleagues read about my Gameboy fiddling and kindly posted up one of his old grey DMGs that was destined for the charity shop to see if I could do anything with it. I decided to document its transition.
It was in the kind of standard condition for a used Greyboy of its age. The case was a bit roughed up and the LCD screen had vertical lines of dead pixels at either end. You can make them out below.
First things first was to see if I could fix that, as if the screen was dud, it would only really be worth spare parts. Luckily, it’s a pretty simple job, and before long the screen was as good as new.
With that, it was time to set about preparing the screen to put a backlight in. The old Gameboy screen was always a nightmare to see, so installing a new LED light source is a must. It’s also a tricky process, involving removing the foil back off of the screen itself. One wrong move and you can trash the whole thing. As it turned out, the adhesive on this particular Gameboy hadn’t corroded away, meaning it was a pretty smooth and simple process.
Next up, I installed a hex inverter chip to ‘bivert’ the screen. The new backlight polarising filter inverts the screen already, and so this step inverts it back to the regular display type, increasing the contrast in the process. It’s fiddly, but drastically improves the clarity. I’m pretty blind, so any picture improvement is a win.
It took a while as I didn’t realise that the backlight kit was missing a crucial resistor, and I had to go through each step to test it all again. A good lesson in not trying to do too many things at once.
Here’s the screen all lit up and biverted.
Next was installing a pitch oscillator that I had had lying about for ages. In other words, a small knob that changes the clock speed of the Gameboy to run faster or slower. What’s the point in that? For games it helps speed up boring parts that you can’t skip, but for music it lets you slow down or speed up things with the corresponding pitch change. Pretty damn cool.
The potentiometer fits into the space where the speaker sits, so it had to go.
I also wired up two RCA jacks for line level audio output. This wasn’t the ideal place to put them, but space was tight because of the other mods. I had begun to install a 3.5mm line out in the same position, but realised that the plastic seemed to be much thicker than in the other model I had done this on, and so the barrel was too short to fit through. RCA it is!
There was a lot of wires in there by this point. Just for fun, I decided to throw in some orange LED lights to give the case a nice glow. By the end of that, it was a bit tricky getting the case to go back together neatly.
At least I used appropriately coloured electrical tape…
The case cutting and drilling leaves a lot to be desired, with rough edges obscured by the buttons and pots… But you can’t really notice. Despite that, I’m pretty pleased with the end result. Everything works, I learned a fair bit, and an old Gameboy has a new lease of life.