I get a crackling audio sound when explosions happen in the metal slug games. I got a z80 error recently but when i turned the neo off and turned it back on it worked fine but i still have the audio issue. Today i felt some of the sound chips while it was on and the yamaha sound chip was running a little hot. There is no trace damage to the board, cart is clean as is the cart slot. Is the yamaha sound chip going bad ?