Main motor jumping

[Pigs Might Fly]

I recently found enough time to get my MCPX out of it's box, with the intention of getting back into flying after about a 12 month break. I found that on start up, the main motor and all three servos would surge up and down on about a 2-3 second cycle, the blue LED on the main board would flash in unison, did some basic fault finding, disconnecting motors & servos, rechecking etc. thought I'd found the problem when the main motor continued to cycle, even when plugged into the tail motor socket. Dragged out a spare (but used) main motor, only to find the same problem, could I have two faulty motors? I wondered about the batteries after 12 months of no use, but the same problem exists on any of my 3 batteries, surely they are not all failing! Any suggestions as to what the problem might be?

[Pigs Might Fly]

Hi, thanks to all of you who have had a look at my post. A little feedback for anyone who might experience a similar issue sometime. I had visions of replacing main board, motor etc. dropped into LHS who fortunately did not have motor or board, so I just bought a battery. It seems that the problem was with my old tired batteries, probably not enough current to run everything so the motor & servos were cycling on inadequate current. Anyway I completely stripped the heli & did some maintenance on servos, bearings etc. so should run fine for a while now - or till I crash it!