So I've been happily making away with these nodeMCU boards now for a while but I came across a strange issue when updating some code on my board.The problem was that I couldn't flash anymore with Arduino's IDE (OR the NodeFlasher tool)
The error I was getting in Arduino's IDE was:
warning: espcomm_send_command: didn't receive command response warning: espcomm_send_command(FLASH_DOWNLOAD_BEGIN) failed
I tried flashing over all the memory with the flash tool but that didn't work, I also tried connecting D3 to 3.3v output, that did nothing. I've also tried holding the flash button down while flashing without any effect.