gorf game board/rom issues

hi i would appreciate any advice on the following issues that i am having with my gorf boardset...

there seems to be issue with my game board...there is no gorf speech (although all other sounds seem to be working fine) and also joysick down doesnt work (up left and right are fine).
i have another spare game board that has a display issue on levels 2 and above (scrolling 1 inch interference bars on left and right of the screen) but the gorf speech and joystick down is working fine.
 
any ideas which components i should consider moving to fix the speech and joystick down?
also after play testing right the way through the different levels i find that the game crashes everytime i kill the boss. i assume that this is due to a bad rom. an error is not indicated in test mode i think... well it displays X but that is not documented in manual so assume it indicates no chip errors. any ideas which rom relates to the boss level?
 
i have a spare rom board that just gives black screen when i use it - but maybe i could just move the boss level rom across?
 
or maybe the crashing is not a rom issue?
 
many thanks for your assistance.
 
- rich