A small change between pre-production PCBs and production PCBs caused all production PCBs to not work. The Gameboy link connector isn’t properly grounded.
The good news is that it’s a pretty simple fix. Simply take a wire and solder it between the two points as shown:
Selling a faulty product is below the standards I hold myself and this shop up to. You shouldn’t have to fix the products I sell you. Because of that, I’m doing a voluntary recall. If you don’t want to fix your own (or you just feel like you should have gotten a working product), please contact me contact me and I will send you a new unit at no cost to you.
If you have any questions or concerns, do not hesitate to get in contact.
Thank you for your continued patience, understanding, and support.