Report "I have had an unused 12year old Shacklock Chefmaster recently installed Model WO570TC serial No EKD 138817. It has a soft touch controller. After turning the oven on eg to bake it starts ok then there is a faint chattering noise and the panel beeps, switches off the oven and comes up with "AO" which I expect is an error code. Please could you tell me what I can do to identify and fix the problem. Today, I phoned F & P and was told that "AO" error code means low supply voltage or faulty controller, I took the covers off to check for loose connections as this could cause voltage drop. Now. on turning the oven on at the wall there is no response at all. The supply voltage checked out at 238v. Is there a fuse to check and where would it be located?"