I finished assembling my printer last night after waiting for some replacement parts, but when I first plugged it in the LCD screen remained blank, despite adjusting the trimmer all the way to the right to maximise contrast. All the other LEDs lit up and when connected to the computer via USB Repetier could connect to the printer and read its status, which pretty much narrowed the problem to the LCD screen or its connection.
I removed the LCD from the front panel to check the connectors and soldering, but at this point discovered that it worked fine when not mounted onto the printer. After a bit of investigation I found the culprit - either the hole in the side panel for the reset button was not correctly aligned or the switch was soldered too far proud from the LCD board, causing the reset button to be permanently pressed. I carefully enlarged the hole with a drill and now it all seems to be working fine, ready for my first attempt at printing.
I thought I would post just in case anyone else encounters the same thing as it wasn’t immediately obvious.