Electric hob broke down after 15 months.hotpoint sent engineer to repair it.replaced touch control panel,still never worked,he said must be terminal block.replaced it one week later,when he switched power on,four standby lights came on for a second and went off,he said hob was ok.and it looks like fault with electrics,he said it was a neutral fault,can anyone explain what this fault is or is he just fobbing me off.he never checked inside of hob after turning power back on.original fault took 2 weeks for hob to die.