I guess I just want bragging rights, but here's the short story of rescuing Pokémon Yellow.

I run "fix your gameboy game for £10" which occasionally I get orders for. This one was a challenge.

First it had a battery swap attempt (I spotted on the melted shell), but it had also suffered A LOT of flux and grim inside and initially I couldn't see any corrosion.

There were solder bridges on the ROM and eventually I spotted that the VCC vias to the ROM were corroded, so I got a jumper in place from the rear to the VCC pin on the ROM and it started booting.

But…not all was well…

The Pokémon Yellow title screen running on a Game Boy
Yellow boots, but …
The game running in-game with the large sprites visibly broken
Although sprites work, large sprites did not…

My guess it was related to the RAM chip (assuming the sprites are built in RAM when they're big) and other reddit posts confirmed this.

The old multimeter is my friend, I could see the power monitor/reset chip wasn't getting power. In fact, the trace was fudged where it joins up to a 10K resistor.

I completely removed and rehomed the resistor, found even more vias that were corroded and using this excellent post to trace out from the reset chip to the RAM, I was able to add two more jumpers and only then did it come back to life:

The Pokémon Yellow board with the rehomed resistor and jumper wires added
In the top left you can see the rehomed resistor and the trace that had been completely removed.

I usually use the hair-thin wires, but I figured if someone was going to replace the battery on this in 5 or more years, hopefully the big blue and yellow wires were shouting I'M HERE ON PURPOSE!

Pokémon Yellow running properly with a battle scene and full size sprites
All good again, and Yellow can battle those pokemon.

I love getting these challenges - and definitely couldn't do what I do without the wealth of info on the web and reddit on the gameboy.

Another game saved from landfill 💪