GB boy modding, screen and speaker repair

This is mostly some notes on things in case someone else needs this information in the future.

After receiving a defective Kong Feng GB boy color (a Gameboy color hardware clone) I search for information about the screen they use since my screen was flickering, but found nothing that helped me. The problems I was experiencing was the color seemed very washed out, and as soon as there where more then just some text on the screen, it started flickering, it got worse the more things it had to display (completely black images where the worst). flickering

Since I couldn't find anything online, I now present my own findings.

Screen: The cause of the flickering was one/some of the pins on the connector that the ribbon cable is plugged into on the motherboard. To fix this I cleaned the ribbon cable and the connector. I also went over the backside of the connector where the pins meet the board with a soldering iron, I pushed gently on the pins downwards and towards the connector, while moving swiftly back and forth since I did not want to get things to hot. ribbon connector

Notes on screen: The screen seems to be resycled from a Canon mg5250. My screen have a 1x0.5cm box shape burn-in in the bottom left corner that makes me think these are most likely taken from old/broken printers. I have myself owned just this printer model, and I remember them being cheap and easy to find. screen

Speaker: While I was fiddling around inside the GB boy, the speaker cable broke off the motherboard. This was easy to fix, since I had already taken note on where it was soldered to. I tried soldering to the obvious speaker pads right next to the speaker, this did not work. The correct way is the bottom left pad next to the speaker and then the right side of the closest 10k resistor. speaker connection

Modding: (66/188 in 1 "flashcart") When the console is started whiteout a game inserted it boots into a list of 66games repeated to look like 188. I wanted my GB boy to feel and behave like a real Gameboy color, so I desoldered the flashcart and the trigger that sits in the cartridge slot. The 2 pads the trigger was connected to then needs to be soldered together, I used a short wire to accomplish this. trigger pads

Modding: Speaker disabled when using headphones. The old revision (the one I have) does not disable the speaker when connecting headphones, I fixed this by gluing the switch I removed from the gamecart slot in a place where the headphones would physically push the switch when they are connected. Then I soldered the switch in between the speaker wire and the main board like this picture

Notes on the 66/188 in 1 "flashcart": The traces going to the flashcart seems to go straight to the cartridge connector. It may be possible the mount the flashcart in a real cartridge. I have yet to try this. If I ever try, I would want to do so to find out if I could reflash it. removed from upper right corner