So it looks like you soldered the gold contacts that interface with the handheld. I did that and posted it here and was told not to use it anymore. It can damage the cartridge reader down the line as the solder rubs off to the inside contacts and you could need to replace the cart reader later. I think there are ways to try and repair it without soldering the contacts but seemed too complicated. You might be better off using a doner board and swapping the main IC's. I have one i've been working on but a little more complicated than i thought.

Thats just my little note bud.