Troubleshooting - Samsung CM1319 Service Manual

6. Troubleshooting
Fa a a
PRECAUTION
. CHECK GROUNDING BEFORE CHECKING FOR TROUBLE.
. BE CAREFUL OF THE HIGH VOLTAGE CIRCUIT.
. DISCHARGE THE HIGH VOLTAGE CAPACITOR.
"WHEN CHECKING THE CONTINUITY OF THE SWITCHES OR TRANSFORMER, DISCONNECT
LEAD WIRES FROM THESE PARTS AND THEN CHECK CONTINUITY WITHOUT THE POWER
SOURCE ON. TO DO OTHERWISE MAY RESULT IN A FALSE READING OR DAMAGE TO YOUR
METER.
. DO NOT TOUCH ANY PART OF THE CIRCUIT OR THE CONTROL CIRCUIT BOARD, SINCE STATIC
DISCHARGE MAY DAMAGE IT. ALWAYS TOUCH GROUND WHILE WORKING ON IT TO
DISCHARGE ANY STATIC CHARGE BUILT UP.
6-1 Electrical Malfunction
SYMPTOM CAUSE CORRECTIONS
Oven is dead. . Open or loose lead wire harness Check fan motor when thermal cutout
Fuse is OK. . Open thermal cutout (Magnetron, cavity) |is defective.
No display and . Open low voltage transformer Check Ass'y PCB when L.V.T is
no operation. . Defective Ass'y PCB defective.
PWN
Check adjustment of primary, interlock
monitor, door sensing switch.
No display and no
operation Fuse is blown.
(10A, 1.6A)
. Shorted lead wire harness
. Defective primary latch switch(NOTE 1)
. Defective monitor switch (NOTE1)
. Shorted H.V.Capacitor
. Shorted H.V.Transformer (NOTE2)
obnONM—
NOTE 1: All of these switches must be replaced at the same time.
(refer to adjustment instructions)
Check continuity of power relay contacts and if it has
continuity, replace power relay also.
NOTE 2: When H.V.Transformer is replaced, check diode and
magnetron also.
1. Key input is not in-Sequence Refer to operation procedure.
2. Open or loose connection of
membrane key pad to Ass'y PCB
3. Shorted or open membrane panel
4
1
Oven does not accept
key input (Program)
(CM1929/1629/1329)
. Defective Ass'y PCB Replace PCB main.
. Open or loose connection of high voltage | Adjust door and latch switches.
circuit especially magnetron filament
circuit
NOTE: Large contact resistance will
bring lower magnetron
filament voltage and cause
magnetron to lower output
and/or intermittent oscillation.
2. Defective high voltage
Timer starts countdown
but no microwave
oscillation.
(No heat while oven
lamp and fan motor
turn on.)
components H.V.Transformer Check high voltage component
H.V. Capacitor | according to component test
H.V.Diode, H.V.Fuse procedure and replace if it is
Magnetron defective.
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