I had all of these issues. Interestingly, I was able to solve it by disconnecting the LCD. I think it may be due to power requirements from some of the larger LCDs being too much, and there being an undervolt. The hint for me was that the screen was coming out with low contrast, and I was reading 3.8V on it (rather than the expected 5 its supplied). To clarify, I was unable to upload sketchesby altimmons - Controllers