https://wiki.pldarchive.co.uk/index.php?title=SEGA_Model_2B/2C/3_Drive_Boards

thanks for the reply
ok so I powered up the 838-11967 (lemans 24 twin) using power from the PC +5v red to Sega yellow cables and black to Sega white
I could see the numbers going up and down as I moved the wheel but 10mins later it stop, and I only could see UUUU on the display reboot and same error.
so I swap over the the pcb from the left car and the the display just had blank but the "." was flashing
 
so i read this topic and order some gals from https://fr.rs-online.com/web/p/spld/1278205

programmed them and now the displays are blank
and checked the 27c512 all ok




will the bottom pcb power up without the top pcb and what does the display show??
that way I can oscilloscope it?? unless is a ram fault  

i try flashing the old ones 

but no change ill order some gal's

or can i send to you to fix??

hi i need help
my lemans 24 has 2 dead pcbs on the driver
i tried to program it see photos

but still no output from the display one show a flashing . on the leds

the other one is dead 

is someone able to help or is njz3 going to make it drive the motor pcb from the 2650 mega??