I would be looking at the connections on the POD, where the plug goes. Give them all a good clean, which you may have already done, wiggle the plug about a bit and each time you have done that switch off and back on to reset everything.
If nothing obvious, have a look at where the pins go through the pcb board of the POD, you may have a dry joint there some where or a break in the solder join to the board.
I have had the same problem with breaks in the solder in the control box as well, so may be worth looking at that end of the pod lead.
Hope this helps
John - PLOD11