battery replacement

Bought this as a broken board/abandoned repair attempt. Seller said it was giving a picture but restarted continuously. He also claimed it was recapped and cleaned from battery corrosion. Board started up to a static corrupt screen. Noticed that pin94 on neo b1 (watch dog enable) had a wire to...

Hi, I'm new to arcades and bought a PGM board (Rev. 5) with Demon Front. When I first played this, I only recognised a little flickering and the highscores. Playing the game was still fine. But then I removed resistor R24 and D2 and replaced the battery with a battery holder. After that it...