Just installed a new Rottendog MPU board in my CFTBL due to battery damage and certain features of game not working. The board was PnP with the the CFTBL newest rom and NVRAM (so no batteries needed anymore) . With the new board on start-up I get a Test Report with "U6 Chksum error". However, the game seems to play correctly and all sounds seem good. Any Ideas???

Restoring to “factory settings” did not correct problem - thanks anyway. It was worth a try!

I am planning to remove the U6 EPROM and re-seat it. My old board did have the L4 rom installed. If re-seating does not work, I will try swapping with the L4 Rom from my original board.

I swapped the L4 rom from my old board to the new board and the problem went away. Now it starts up with no errors! Must have been a bad EPROM on the the new Rottendog board. I have reached out to Keith at KsArcade.net from where I purchased the board with the new EPROM.