Midea induction cooker power is normal. Display 00:00, but all the keys are not responsive, some people said to change the key pad, but I changed a new still can not do?

The most common fault is with LM339 integrated circuit 4,5, 8,9 pins connected to the large resistance value resistance break, (RC1, RC2, 510K2W. RB1, RB2, 270K2W. R501, R502) makes the LM339 pin can not get the detection signal, and can return to normal after replacement. In addition, please check whether the third pin of TA8316S has 18V voltage, if not, check whether Q201 has breakdown, ZD201 has breakdown, high frequency capacitor 0.33uf, large capacitor 5UF failure? Finally check whether the coil is locked.