07-28-2019 10:11 PM
I use chinese replacement catridges and looks like one got unseated and the printer head/cartridge carrier got jammed and printer would flash 5100 error.
I had to pop the small cover on the scanner bed - lower right corner - and then push the cartridge carrier by hand to get it past the obstruction. Popped all the catrridges and cleaned the printer head as per one of the very good videos on youtube. I couldnt find any other instance on the internet of a problem similar to mine, so documenting it here in case someone else gets it too. Hope it helps.