System doesn't turn on, but the speaker makes a popping noise.

Hi, whenever I try to turn on my Game Boy Color, the speaker (or headphones when they’re plugged in,) makes a single pop/click sound, and the system doesn’t start up with no LEDs turning on either. I already tried opening up the system and tried cleaning the battery terminals, but it still doesn’t work. Everything looks completely normal on the inside, so I’m not sure what’s wrong. Can someone please help?