Rambo 1.3a heatbed output won't turn off (Please Help)

Hey guys, I have just finished a self-sourced Taz build and am using a 24v supply with a rambo 1.3a controller. I had the printer running great yesterday and decided to wrap up the final electronics today, including a cooling fan for the board. I accidentally shorted out the fan connections with my multimeter trying to determine the positive output, which blew the F3 fuse that controls the logic. I wanted to get the logic back up and running so I swapped out the F2 fuse into the F3 location temporarily. Now the logic is running, however, the heated bed output is constantly on, and I cannot connect to the board through any host server, I have tried repetier, pronterface, and cura, all 3 of which report "[ERROR] Errorrinter halted. kill() called!." LED 6 is constantly on whenever I turn the power source on. The driving signal on the gate of the Q5 mosfet is constantly at 5V, which explains why the heat-bed and LED 6 are constantly on and also verifies that the mosfet is working properly. I have tried flashing the firmware multiple times and the issue persists. I have exhausted all my resources and am afraid that I have permanently damaged the ATMEGA2560 chip on the board, rendering the board useless. Please, if you have any suggestions that I have not attempted already feel free to propose. I should have mentioned I am an electromechanical engineering student, so I am fluent in reading schematics, just made a stupid mistake and am paying the ultimate consequence.