Gameboy Not Booting Games Properly. Blank Screen & No Sound with Game.

I recently bought a non working Play it Loud Gameboy DMG online. I opened it up and gave everything a good cleaning. There was very little to no corrosion. I only found a very tiny patch on one game reader pin near the bottom of the reader that I cleaned. When I turn the system on with no game, it loads and stays on properly. I can also hear the white noise of the speaker. If any game is inserted, the Nintendo logo comes down and makes the iconic beep. After the beep I hear a small flicker in the white noise of the speaker and both sound/screen cut completely. The red light remains on as well. I'm not well versed on using a multi-meter, so I'm not quite sure where to start with diagnosing this issue.