Dual Extruder Woes [Rostock Max V2]

[tr15070]

I'm trying to install a Chimera dual extrusion hot-end onto my Rostock Max V2. I've wired it all correctly to the best of my knowledge but am now stuck. When after I plugged in the second extruder's stepper motor, I noticed the status LED and the smart LCD connected to my RAMBo 1.2 turned off, and the red LED at LED 5 is now on.
I've changed all the fuses, switched it on and off to no avail. It also does not connect to MatterControl but the RAMBo does show up in my device list. The board is still getting power as I've checked the PSU and the fan I've wired to the MOSFETS switches on with the printer.

Happy to clarify further, an insight on what LED 5 means and what might be happening greatly appreciated!

[czecht]

Have you find a solution for your RED LED?