Diplomat Hob

I was looking at a fault with a Diplomat APL 1304 for a family relative.Problem is appliance is tripping mcb at consumer unit when a specific ring is switched on.Any way i dismantled the appliance to visually examine the hob ring and found no apparent visual damage ie broken/damaged element.I disconnected the wires from the stat to the ring and re energised the supply.When i turned on the control knob to the maximum position at the first attempt it immediately tripped the mcb (i then thought the control stat/switch was the culprit).However i re energised the appliance again and again set the control knob to the maximum position-this time the mcb did not disconnect.My suspicion is on the hob ring?

Any suggestions much appreciated.

IR testing of elements of any type is par for the course beyond a visual. 

Before you start replacing parts why don't you test the components and their associated wiring first? 

I recon that you have an IR fault on another circuit,,,, testing would be the first point of call