What part should I replace?

I was messing around with my Gameboy, since i was waiting for a battery replacement i wanted to try something else and connect a normal USBcable but with the end stripped so I could connect it where the battery usually is connected. The screen flashed for a bit and then no power. Then I realized that i might have fried something inside. Don’t really know if it’s part of the charging port or the whole motherboard. I’ll be glad for an answer.