Hi
U8glib sends an init sequence to the display immediatly after reset. This init sequence might be corrupt or is not recognized by the display.
Some possible problems:
- Your arduino is too fast, the display is not yet ready to receive the init sequence:
- The reset of the display takes too long, the init sequence has been sent, but was not received.
- Wires are unstable (connect problems) or are too long.
- Timing of the data transfer is too fast for your display
- Mode selection (parallel vs. serial) has a problem (or is missing or floating...)
I would start with the hardware: Check wires and their connection. Did you correctly set the mode for your display?
You might also provide more information: What is the mode? Parallel, seriel? Can you provide a picture?
Oliver