We could check it on the -200 at SWA by just moving the throttles up when we are at the gate.
Well you could...but the engines would have to be running.
On the -200 the system works on advancement of the EPR gauge indications and not the thrust levers. You can check it at the gate on the -300's on up.
(From an eye witness of a captain who made a very embarrassing call to MX!)