Hi 4 all,
I use this LCD display for Arduino 328 :
how can i print a variable on the lcd ?
question and suggestion...
Have you swapped LCDs on the MEGA to make sure they both work?
Assuming you verify the LCD is fine, I would suggest you make it work without the shield first. You can find plenty of code and wiring examples for that at arduino.cc. The if adding in the shield causes the problem, DFRobot support would be able to help you. But until you have verified that the LCD and code to drive it work, it ia hard to pinpoint.
In general, yes, you should create new threads. Now that email is working again, the OP is getting all of this and possibly getting confused.