ORIGINAL: tazzzz
I dont know about the control surfaces,,but I can see the throttle linkage moving back and forth,,,,,,,none of my other planes do this,,thats what I cant figure out.
TAZZZZ
Unfortunately you'll have to isolate one component at a time, could be the Receiver, a servo, a switch, battery lead, servo extension,,, metal to metal contact somewhere?
I'd start by unplugging or replace each component first with switching out the Receiver, it it's not that then one servo at a time, plug the battery directly into the Rx to see if it's the switch, etc.
good luck