Granz induction cooker common failure repair-1

I. Granz C18B-IMPl induction cooker, after power on the buzzer will ring, but the key is not responsive

The phenomenon indicates that the Mcu system is normal. Check the components are no soldering problems, 5V power supply is also normal. I also found no problems with the wiring. Later, using a multimeter to measure the connection, found that the ICL (74LSl64) ⑧ feet of the line in a broken, resulting in the loss of the clock signal sent by the MCU, making the keyboard scanning failure. Connect the induction cooker back to normal.

Granz induction cooker common failure repair-2

Second, Granz C20B-IMPl induction cooker can be heated and all functions are normal, but the timing function of the double “8” display are missing! A stroke, power on and found that stroke C can not light up.

This display is a *** cathode connection, as shown in Figure 5-17. This fault obviously belongs to the corresponding pin of field c no signal over. Along the c pin to check the connection, found in the jumper J4 there are particles of slag so that the copper wire and jumper short circuit, resulting in the signal is bypassed.

Granz induction cooker common failure repair-3

Three, Granz C18B-IMPl induction cooker, power on the buzzer will be sounded, but after power on the work of the keypad on the light has flashing

The function of the machine is basically normal. Normal, but in the heating state indicator lamp irregular flashing, and the higher the power the more obvious. Check the key board 5v power supply is also normal. Since the failure phenomenon is related to the power size, we can be sure that the problem comes from the interference signal. In the key board on the ICl (74Lsl64) ① foot (5V power supply filter) external capacitor c1 ends in parallel with a capacitor of the same value, the fault disappears. Remove c1, found that there is no capacity. Replace a 100μF/16V capacitor after the fault eliminated.

Granz induction cooker common failure repair-4

Four, Granz C18B-IMPl induction cooker, power on the buzzer will sound, but the key does not respond

The phenomenon that the Mcu system is normal. Check the components are no soldering problems, 5V power supply is also normal. I also found no problems with the wiring. Later, using a multimeter to measure the connection, found that the ICL (74LSl64) ⑧ feet of the line in a broken, resulting in the loss of the clock signal sent by the MCU, making the keyboard scanning failure. Connect the induction cooker back to normal.

Granz induction cooker common failure repair-5

Five, Granz C20B-HYPl induction cooker on soon after the display E2 and alarm shutdown, resulting in the inability to heat

E2 is the meaning of the protection of the pot. Mcu20 pin detects the signal level from the transformer. When detected below 0.6V is to enter the protection state, repeat the detection of children if they are too low, then automatically shut down. The circuit belongs to the power type of pot detection. Measure the Mcu20 foot to ground voltage, check the maximum value of the pot state is less than O.2 V. Follow the D14 forward level, found that the adjustable resistor VRl resistance value of 5k &# 937; to nearly 20k &# 937;, replace the adjustable resistor after working normally. As long as the Mcu20 feet of voltage is lower than 0.6V, will be judged as no pot state. So any device between the output circuit of the transformer to Mcu20 feet (such as D2 ~ D5, VRl, R57, D14) open circuit will appear E2 failure.

Granz induction cooker common fault repair-6

Six, Granz C20B-HYPl induction cooker, work for a longer period of time, the fire is not enough

Tests, found that the induction cooker after working continuously for an hour, it began to Intermittent heating, and sometimes E8 alarm shutdown, resulting in insufficient fire. The sampling resistor R1l is reduced to 4.3kΩ, as shown in Figure 5-18. After the sampling resistor is reduced, it is equivalent to raise the temperature protection point of the induction cooker, but it has some effect on other menu functions.

Granz induction cooker common failure repair-7

Seven, Granz WP700 (WP700L17) type mechanical microwave oven cavity fire

There are two kinds of phenomena in the cavity fire. One, due to poor maintenance, the magnetron energy output (waveguide) serious accumulation of dirt, microwave oven work will be the first oil heating, the temperature is high natural formation of fire. Furnace cavity, energy output, vent clean, regular cleaning and maintenance, fire that is eliminated. Second, doubling the pressure rectifier high-voltage wire and chassis distance is too close or touch the shell, if the high-voltage wire insulation is poor or humid air that occurs arc. Adjustment away from the pressure wire away from the chassis, if necessary, add insulation board insulation board insulation.

Granz induction cooker common failure repair-8

Eight, Granz C18B-HYPl induction cooker button function is normal, but can not be heated and display E2 alarm and shutdown

Not after power on to check the bridge stack! The rectifier voltage is 305V, normal. Then measure the heating coil disk voltage is 0V. careful observation found that L1 of a solder joint desoldering, after welding normal.Fsb Wanguanshu Sheng small appliances

Granz induction cooker common failure repair-9

Nine, Granz C20B-IMPl induction cooker power on! After no beeping, the key is invalid

The reason for this kind of failure is usually that the MCU is not working properly. Check the 5v power supply, crystal circuit, reset circuit. Found that C31 desoldering, resulting in the MCU can not be normal reset, as shown in Figure 5-19, after replacing the welding is normal.Fsb Wanguangshusheng small household appliances

Granz Induction cooker common failure repair-10

Ten, Granz C20B -IMPl induction cooker burst after one power on (fuse burned off open circuit).

Induction cooker internal power rectifier/feedback/comparison circuit, as well as synchronization circuit of any part of the failure, will lead to burst. Through inspection, the machine was found to be used for synchronization of the R5 resistor open circuit, as shown in Figure 5-20. R5 was originally 120kΩ/1W metal film resistor, changed to the same value of 2W metal film resistor, the test machine is normal.

Granz induction cooker common failure repair-11

Eleven, Granz C20B-IMPl induction cooker, the water boiling delayed shutdown

Burning water automatically shutdown function is through the detection of Mcu ④ foot of the voltage value to realize. voltage value to realize, when the set water boiling temperature is reached, delay a few minutes to turn off the machine. Measuring the level of pin ④ when heating, the temperature gradually rises and the voltage keeps getting higher, and no longer changes when the voltage rises to 1.5V. Suspected thermistor performance deterioration, replacement of the function back to normal.