Hello Richard.

It still returns an OK status byte. I am certain because i have implemented my own Reset routine by holding a key pressed for about 8secs which is executed by the Timer 0 ISR. If the LCD conttroller didn't return the Status OK byte, then the Timer 0 ISR would halt since i also use it to print to the LCD.

I will try using the power network ground as a common voltage ground on all boards. I hope it will work.

I don't remember any command that turns on the display but i will try it again.

Thanks for the tips.