Rangemaster Classic 110 Dual Fuel ( Plate Warmer Faulty)?

My Rangemaster Classic 110 has developed a fault with the Electric plate warmer. My wife was heating up a couple of plates on it, after a few minutes it suddenly gave a loud bang, some sparks appeared and it tripped the circuit breaker. I think a wire has come off as i have heard this could be a common fault. Does anyone know where i could get specific dismantling instructions for the plate warmer??