After a failed print I realized the cooling fan was not turning on even though it was supposed to be 100%. While trying to probe some pins on the cables going toward the printer head assembly, something might have gotten shorted and the machine turned off. I also heard a short beep and afterwards it won’t turn on. I checked the power supply and it seems to be working correctly so I opened the control box. There is no apparent damage and the fuse is intact. There is a small LED that is occasionally blinking labeled “R” even though the power is disconnected. Is there a way to determine if the control board is damaged, and if so, how can I get a replacement?
There are 3 fuses. The big 15 amp one is just for the heated bed. The two 1 amp ones on the board that look like grains of rice are the ones you most likely blew. Replace those and if it still won’t power on, replace the board.
Thanks, I missed those. It does look like one of them is blown so I will try replacing it first. Now I have to figure out how to actually get it out…
Actually they are 5 amp fuses. 
Well those ones aren’t anymore. They melted.
Ok, I got a new board from UltiMachine and got it installed. It looks its mostly working as I can update the firmware and move the head around using Cura. The LED display is turning an the button knob will beep when I press it down but it won’t display anything. I am still working with tech support to see if I can resolve it but was wondering if anyone here has seen something like this. The best I can tell, everything is plugged in correctly.
The LCD leads are unfortunatly interchangable. it is possible you have them swapped. The OHAI kit documentation kind of shows which cable should be where. https://ohai.lulzbot.com/project/f10f9900-84aa-4cc9-9637-cd226f0a5d8c/a16b1f2d-5c1f-47fe-a83d-9d68cca5d62c/
If its not that, it could be melted too. but a new LCD board is only $40 or so.