This Game Boy Micro was destroyed by corrosion — now it’s fully working again
This Game Boy Micro came to me in pretty rough shape. The motherboard had what looked like coffee spilled inside of it at some point, and the corrosion had gotten bad enough that it actually ate through a via.
I started by thoroughly ultrasonic cleaning the motherboard, shell, buttons, and button membranes. After cleaning the board, I began inspecting it for corrosion and checking the affected circuits.
I used a known-working Game Boy Micro to run continuity checks and compare the board against a good reference. That allowed me to track down the broken connection rather than just blindly running jumpers.
I also used a fiberglass pen to carefully remove the solder mask around suspicious areas so I could inspect the vias underneath and make sure there wasn't any hidden damage.
I found one pad with four vias connecting together. Two of the vias had been damaged by corrosion, but the other two were still intact and providing the connection, so there was no need to add a jumper there.
I eventually found a via that had completely rotted away and was actually breaking the circuit. After tracing where that connection was supposed to go, I repaired it with a single wire jumper.
While I had everything apart, I also replaced all of the tactile switches for the volume and L/R buttons as preventative maintenance. These switches are prone to becoming unreliable on the Micro, and since I already had the board apart, I figured I might as well replace them. The switches are the same type used in the Nintendo DS Lite.
One other little repair tip: ultrasonic cleaning the board after installing the new tactile switches does a surprisingly good job of flushing flux out of the switches themselves.
After all of that, the Micro is now fully functional again.
I'm still working on the cosmetic side of the restoration, but considering what this thing looked like when I started, I'm pretty damn happy with the progress.
One thing I think is worth emphasizing with these repairs: multilayer boards require a lot of attention to the vias, especially on Game Boy Micros. Corrosion can get underneath the solder mask and damage connections that aren't immediately obvious from looking at the board. Don't assume a trace is intact just because it looks intact.
With Game Boy Micros becoming more expensive, I'd really like to see as many of these things kept alive as possible instead of being written off because the board looks too far gone.
Hopefully this inspires someone else to take a shot at repairing one rather than giving up on it. There are a lot of these old handhelds that are still perfectly salvageable with a little patience and some careful troubleshooting.