Hello! So I was just replacing my hotend nozzle and had the tweezers around the actual hotend holding it in place when all the sudden my whole lulzbot taz 6 turned off and now will not turn back on. I am pretty sure I didn’t hit anything (although one of the ends of the tweezers was near the back towards the big red wires, but again pretty sure i didn’t pull on anything). If something were to have happened it would be compressing the wires which should not break them. Do you know what could have happened? I tried restarting my machine and when the switch is flipped to on nothing happens. Any advice would be amazing! I was trying to replace the left nozzle on the dual head V3
It sounds like what you have here may be a blown fuse on your Rambo. Does the red power switch still light up? If it does, then I think that it is the F3 fuse on your Rambo that you will need to replace.
Here is a picture from Reprap wiki that highlights the fuses on the Rambo: https://reprap.org/wiki/File:Ramb1-2-fuses.jpg
The fuses that are on the board are a Nano2 surface mount fuse, and you can purchase them here: https://www.lulzbot.com/store/parts/5-amp-nano-polyfuse-x3
There is also a test you can do before you purchase the fuses to 100% confirm that it is the F3 fuse that is the root of the issue. You can swap the F2 and F3 fuses, as they are the same type of fuse, then power on your printer. The LCD should light up, but the motors will be unable to move. This way you can see that you only have one blown fuse (now in the F2 fuse spot) on your board that you need to replace.
In this case, it sounds like you may have fried the fuse due to the printer being on while you were replacing the nozzle. When using metal on the hot end, it would be best if the printer is off to prevent anything shocking the Rambo through the 5V line.
Thank you so much! That is exactly what happened lesson learned. 