SUPOR induction cooker shows normal, can not heat any failure
1, after power on standby, test drive amplification circuit, triode Q9 collector to ground +18V voltage is normal, measuring comparator (ICID) tenth feet, inverting input to the ground, +4.8V voltage is normal. When the voltage is low, the comparator (ICID) is damaged. Measure eleventh feet, the same phase input to the ground, the +0.4V voltage is normal, when the voltage is low, then the capacitor C14 and C15 leakage. Test thirteenth pin output to the ground, +0.2V voltage is normal, when the 0 voltage, then the transistor Q8 (base B and collector C), capacitor C21 breakdown, or comparator LM339 (ICID) damage. After replacing the damaged components, the machine will be restored to normal.2, measuring comparator (IAID) tenth feet, eleventh feet, thirteenth feet, voltage is normal. However, when the fault is not eliminated, the diode, D17, D19, forward resistance should be checked for greater or open damage. When diode, D17, D19 and components are damaged, they cause "alarm not heating" fault. After replacing the damaged components, the machine will be restored to normal.Four, LC resonant capacitor:1, to measure the electromagnetic oven power supply high voltage power supply circuit of +305V voltage is normal, the electrolytic capacitor EC6 to +18V voltage is normal, three terminal regulator IC3 and OUT on +5V as normal, and the voltage comparator LM339 voltage on each foot are normal, it should replace the LC resonance capacitor between C3, check the comparator LM339 each foot with the main circuit circuit is broken open "". (when the C3 is damaged, it also causes "no alarm heating" fault)2, when the LC resonance capacitor C3 capacity is too large, leakage, failure, breakdown, and +305V filter capacitor C2 failure, will lead to IGBT appear indirect, direct, damage.
When the electromagnetic oven "alarm heating" fault, fault scope: power supply of high voltage power supply circuit, synchronous oscillation circuit, drive circuit, LC resonance capacitor which has a component damage, which can lead to the electromagnetic oven "alarm without heating" fault.
