I bought two gameboy colors (gameboys color?) from j4u to fix up and mod. the one on the left was sold as "needs repair" but worked fine, especially after I cleaned the button contacts. the one on the right was sold as "doesn't work" and has... let's say *extensive* corrosion damage. the pics show what it looked like after my attempt to deal with the corrosion and removing the negative battery terminal (which didn't even have continuity from front to back)

surprisingly, the screen of the corroded unit works perfectly fine. I think the board itself can be saved if I track down and patch all of the corroded traces... right now I don't even get continuity from ground to the power switch 😬 definitely a challenging fix (wayyy more complicated than anything I've tried before) but could be fun to try! at worst I have a broken unit that I can scavenge parts from later

so I thiiiink the problem with ground connectivity was simply that the DC barrel jack had completely corroded. I desoldered the jack and then jumped the contacts that would have been bridged if the jack was unplugged and suddenly I get ground connectivity to all the right places. this is encouraging, and the best case scenario is that there isn't actually any damage to the traces or vias and I can just turn this thing on (when I get replacement battery contacts)

of course the A/B/select/start button contacts are not going to work (the corrosion wore away most of the copper), but I can get replacement contacts (https://www.etsy.com/listing/1214538508/game-boy-color-full-button-board-kit-for)... though I still need to remove a bunch of corrosion so I can actually solder those replacements in place

oh my god y'all. it's aliiiiive

now the question: do I put this corroded motherboard that I brought back to life into my expensive boxy pixel case (with the fancy aftermarket screen), or do I use the motherboard that didn't require any restoration? I've already had to perform some of the steps necessary for the boxy pixel mod on the corroded board, in the process of fixing it (i.e., desoldering the battery terminals), and I think I'd like knowing that my frankenstein's heart beats in the fancy case

oh also I'm going to put clicky button switches on the corroded board, which I think could be cool with the aluminum case. ON THE OTHER HAND, there may be as-yet undiagnosed problems with the corroded board, which would suck to deal with on my "daily driver" (which is what I'm hoping the modded gbc will be, at least for a little while). decisions!

this is the boxy pixel case I got btw: https://www.boxypixel.com/collections/game-boy-color-pocket/products/pocket-gbc-machined-aluminum-shell?variant=39754661232682 (it is VERY cool)

damn it looks so cool in the translucent case with all of my repair work showing. reconsidering whether i should put this board in the boxy pixel case!

decided to put new battery contacts in so i could use it in this case. here's a video of it working! since the "it's aliiive" post: i bypassed the voltage divider contrast potentiometer (with some regular resistors i had on hand) to make the stock screen work reliably; i replaced the volume potentiometer and the big capacitors; i fixed like five broken traces around the speaker and headphone jack; and i installed new button contacts (froggocustoms tactile switches!)

the headphone jack is still pretty crackly, and you have to jiggle it to get both channels to work. but: it DOES work, and reliably switches to the speaker when the headphones are unplugged, which is more than it was doing this morning. (at this point i think the only fix would be to replace the jack)