Yesterday was a sad day.
I have unfortunately misconnected Pickit3 to the PIC18F4620 board I'm working with. I'm not sure exactly, but I think I have shifted Pickit3 "left" so that MCLR pin went into VDD pin, etc. The board was energized during the event. After the event the microcontroller instantly went dead - no stuff displayed on LCD, no led blinking, no nothing. I can connect to the chip via pickit and query it's ID, but can't programm it anymore. Even more, the relay that's connected to PB5/PGM pin is buzzing when I try to programm (I don't use LVP).
Nevertheless it's strange - MCLR/Vpp shouldn't be high voltage when not programming, should it?