*HELP* DDJ-SX2 has a dead channel!!

Hello fellow friends, 

My Pioneer DDJ SX2 purchased new at the beginning of last year all of a sudden has a dead channel four - during the boot up process as the unit is switched on the LED at the top of Channel four will flash on as all of the LED's do, however when the unit settles into it's "on" position, Channel four's white "load" LED at the very top stays static on ... this prevents me from using the channel completely. It is 100% dead ... How can I fix this? Is there a master reset somewhere?