Quoted from jordan:
It really helped.I am almost at the point of playing. The game plays but i have no sound nor Display.
It starts with the Data east display and then nothing. The game seems that plays fine without them.
I should say that i upgrated the CPU rom to A1.12 without touching the display or sound roms.
Do you believe it is related to this?
I am facing a wall .
As i have posted earlier when i power the game i have a display version message with the version but then nothing on display.
I can feed credits and play but without sound and display.
I have checked voltages in Sound board and are fine.
Display is also fine as i have the initial display msg.
I cannot also enter into audit mode.
The door switch , Green and black switch are tested also ok.
Even if i keep up or down the green button, when i press the Black button i enter in Diagnostic.
There , i can move only every 2 steps and i cannot really change the settings (Only a few of them ). For instance , audit sound stays into No ,but i can change gave level to Easy or Moderate.
I have changed the 6264 ic with an anypin Nvram as i have removed the Battery
Also something weird is that a "Command 80 " flashes randomly on display.
I will appreciate if someone has an idea of what to search for.