intermittent alarm 4306 amplifier ready signal error

so i am working on a up6 xrc 2001 that has been giving us intermittent alarm 4306, amplifier read signal error on axis L. i can reset the alarm, restart the servo power and the robot will work fine again, some times for a few minutes, sometimes it will run for the rest of the day with no more alarms. i would like to get this figured out and fixed before the robot craps out all together, but not sure where to start.

since these parts are NOT cheep, i have a running ea1400, can i swap the wrca boards between robots to see if the problem stays with the up6 or if it fallows the wrca board to the ea1400. will swapping the wrca boards out be plug and play or will i mess up by abs data and have to remaster the robot? or would i be better off swapping the amplifiers out and leaving the wrca boards with there robots. i dont want to mess up my abs data on the ea1400 and risk both my robots being down.

Quote from Robodoc

You can swap the WRCA cards as long as they have the same software version.

how do i tell if the boards have the same software version? i know they have the same part number and they are both rev c [1][ 2][ 06].