R-7500AT
31
[3] Check in the event of no microwave cooking
*1 In case of the magnetron failure, check the operation of the antenna lower assy and/or the antenna upper assembly after
replacing the magnetron.
*2 Disconnect only the
inverter unit terminals M and AC3. Then measure voltage between CN -A pins #1 and #3 with an analog
tester while performing heating operation.
*3 Connect the harness to the inverter unit (M, AC3) and put the water load into the oven cavity and start the microwave cooking.
YES
YES
YES
YES
NO
NO
NO
NO
Check of high voltage sections is very dangerous. Therefore, disconnect the main power and wait for at least one (1) minute before
starting the check.
NO
YES
Remove the outer case cabinet.
(Function is normal.)
(Function is normal.)
(Inverter unit M, AC3, CN-A and F&FA, and magnetron F and FA)
(Function is not normal.)
(Function is not normal.)
Replace the control board.
Is there a voltage of about 0.9 V DC between the
inverter CN-A pins #1(negative) and #3 (positive)?
*
2
Replace the magnetron.*1
Check is finished.
In this case, check the high-voltage
diodes (D120 and D121) of the
inverter unit for a short circuit.
Correct the wiring.
Completely insert the harnesses.
Is wiring on the high voltage side correct?
Have the terminals been completely inserted?
Is there continuity between the magnetron terminals?
Is there a short circuit between the magnetron heater
terminal and any metal part of the magnetron body?
Replace the inverter unit.
*
3
Disconnect the harness from the inverter unit (M, AC3) and
connect the main power and start the microwave cooking.
Caution: Do not let the disconnected harness earth or short-circuit.
Are the magnetron cooling fins easily deformed?
Has the magnet cracked?
NO
NO
NO
YES
YES
YES
YES
NO
Is there a voltage of 230 - 240V between the
primary terminals to the inverter unit(M,AC3)?
Adjust the latch hook position.
Check the interlock switch.
Is the interlock switch ON?
Is the blower motor running?
the blower motor terminals?
Is there a voltage of about 230 - 240V between
Replace the blower motor.
Replace the relay unit.
(Function is
not normal.)
(Function is
normal.)
