COMPONENT TEST PROCEDURE
CAUTION NEW. H.V.
1. | High voltage is present at the high voltage terminal of |
| the High Voltage Inverter (U) including aluminum heat |
| sink during any cook cycle. |
2. | It is neither necessary nor advisable to attempt mea- |
| surement of the high voltage. |
3. | Before touching any oven components, or wiring, |
| always unplug the oven from its power source and |
5.Inverter Power Supply (U)for USA only
DO NOT try to REPAIR this H.V. Inverter power supply
(U).Replace as whole H.V. Inverter(U) Unit.
DO NOT TOUCH (HOT/HIGT VOLTAGE)
discharge the high voltage capacitors. |
1. Primary Latch Switch, Secondary (Secondary Latch |
Switch and Power Relay B) Interlocks. |
(A)Unplug the lead connectors to Power Relay B and verify continuity of the power relay B
(B)Unplug lead connectors to Primary Latch Switch and Secondary Latch Switch.
(C)Test the continuity of switches at door opened and closed positions with ohm meter (low scale).
Normal continuity readings should be as follows.
| Door Closed | Door Opened |
Primary Latch Switch | 0 Ω (close) | Ω (open) |
Secondary Latch Switch | 0 Ω (close) | Ω (open) |
Power Relay B | Ω (open) | Ω (open) |
2. Short Switch & Monitor
HEAT SINK
CHOKE COIL
CURRENT
TRANSFORMER
RESISTOR
SAND BAR
PCB
HIGH BOLTAGE
TRANSFORMER
FILM CAPACITORS
VARISTOR
PRIMARY WINDINGS
SECONDARY
WINDINGS
HIGH VOLTAGE
DIODES
(A)Unplug lead wires from Inverter Power Supply (U) primary terminals.
(B)Connect test probes of ohm meter to the disconnected leads which were connected to Inverter Power Supply (U).
(C)Test the continuity of short switch with door opened and closed positions using lowest scale of the ohm meter.
Normal continuity readings should be as follows.
Door Opened | Door Closed |
0 Ω | Ω |
3. Magnetron
Continuity checks can only indicate an open filament or a shorted magnetron. To diagnose for an open filament or shorted magnetron.
(A)Isolate magnetron from the circuit by disconnecting the leads.
(B)A continuity check across magnetron filament terminals should indicate one ohm or less.
(C)A continuity check between each filament terminal and magnetron case should read open.
ANTENNA
ANTENNA GASKET
DO NOT TOUCH 4
DANGER HIGH VOLTAGE
Test if failure codes of H97 or H98 appears by doing the following procedure. It is recommended to use an AC line input current Ampere meter for testing.
Test 1
A.Program DPC.
1.Tap Clock
2.Tap TIMER
3.Tap START
4.Tap POWER LEVEL
B.Place 1 liter of water load into oven cavity.
C.Unplug 2 pin H.V. lead wire connector CN703 from magnetron tube.
D.Program oven at High power for 1 minute and press start.
1.After approximately 15 seconds, oven displays H98 and stops oven.
2.During oven operation, input current is approximately 1.0 to 1.7A. If both 1 and 2 are OK, please proceed to test 2.
COOLING FIN
| INPUT AMPERE | FAILURE CODE |
Unplug CN703 | 1.0 to 1.7A | H98 |
.
Test 2.
Continued from Test 1
MAGNETRON CASE
SCALE
A. Unplug 3 pin connector, CN701
B. Set oven at High power for 1 minute and start.
HIGHEST | FILAMENT | |
OHM | ||
TERMINALS | ||
SCALE | ||
|
1.After approximately 27 seconds, oven displays H97 and stops oven.
2.During oven operation, input current is approximately 0.4 to 0.8A
| INPUT AMPERE | FAILURE CODE |
Unplug CN701 | 0.4 to 0.8A | H97 |
|
|
|
If both 1 and 2 are OK, the Inverter Power Supply (U) can be determined OK.
4.Membrane key board (Membrane switch assembly)
Check continuity between switch terminals, by tapping an appropri- ate pad on the key board. The contacts assignment of the respective pads on the key board is as shown in digital programmer circuit.
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