Wow, I haven't seen a video with the MS Video 1 codec since the days of postage stamp-sized clips on a 2X CD-ROM drive... Thanks for the tip to play it in VLC.
I haven't seen that specific problem before, but a few things come to mind:
1. Prior to installing Dexter, was the game working properly with an LD-V1000 or conversion card in LD-V1000 mode? If so, it rules out a number of issues. If not, there are several things that have to match for everything to work correctly:
- Game PCB revision (A, A modified for LD-V1000, C)
- Player type DIP switch settings (for specific ROM revision in use)
- "W1" jumper on rev C game PCB (wire installed for PR-7820, no wire for LD-V1000)
- Dexter mode selection (LD-V1000 or PR-7820)
2. Re-seat the interface cable on both ends. Look for bent/broken pins on the end that connects to the game PCB. (A missing bit on the data bus could cause it to get confused about where to search and what frame is being displayed.)
3. Hold down the MODE switch on Dexter for 2+ seconds. This will put it into auto-detect mode, and it will choose LD-V1000 or PR-7820 mode depending on what it sees from the game PCB.
I hope this helps!