One of them has stopped working. In Quartus I can still see and program the device but when I start it up the LCD turns on and then turns off (in a second or so), with just the power LED on.
If I blank the SPI flash i get the typical behaviour of the LCD backlight turning on and both LED’s turning on as well. All voltages look correct. But as soon as I flash a firmware the behaviour mentioned above happens.
The only change to the device was replacing a broken LCD with a new one.