Dissasembly of Vauxhall/Opel Astra GTE digi dash

Rainbow cable - 1990 digi dash Yellow cable - 1989 digi dash The 1990 dash starts up but doesn't go into operational mode. If you go to 1:16 the base of the crystal is badly corroded. I not sure if the start up sequence requires the uP. Start up sequence here:    • Startup of Vauxhall Opel Astra GTE digi da...