Filter
Top Products
Trouble Related to Digital Programmer Circuit
SYMPTOM
No display when oven is first plugged in.
Oven is dead.
CAUSE/CORRECTIONS
STEP 2
Shorted Circuit of ZNR,
L.V.T., Oven Lamp etc.
Replace DPC
LVT
➝ Step 3
ZD10, Q10
➝ Step 4
IC-220
➝ IC-1, CX320
STEP
1
2
3
4
CHECK
Fuse pattern of DPC
Low voltage transformer (LVT)
secondary voltage
IC-1 pin 8 voltage
(Emitter of Q10)
IC-1 pin 10 voltage
(15 pin of IC-220)
RESULT
Normal
Open (NOTE)
Abnormal 0V
Normal
Abnormal
Normal = 5V
Abnormal
Normal
NOTE
Procedure of fuse pattern repairing is as follows:
1. When the fuse pattern (PF2) opens.
(1) Remove the jumper wire (PF1).
(2) Insert the removed jumper wire (PF1) to “(PF2)” position and solder it. If both “PF1” and “PF2” fuse patterns are open, please replace DPC.
2. When the fuse pattern (PF4) opens.
(1) Remove the jumper wire (PF3).
(2) Insert the removed jumper wire (PF3) to “(PF4)” position and solder it. If both “PF3” and “PF4” fuse patterns are open, please replace DPC.
NOTE:* At the time of these repairs, make visual inspection of the varistor for burning damage and examine the transformer with tester for the presence of layer short-
circuit (check primary coil resistance).
If any abnormal condition is detected, replace the defective parts.
SYMPTOM
No key input
No beep sound
Power relay A(RY-2) does not turn on
even though the program has been set
and the start pad is tapped
No microwave oscillation at any power
setting
Dark or unclear display
Missing or lighting of unnecessary
segment
H97/H98 appears in window and oven
stops operation. Program High power
for 1 minute and conduct following test
quickly, unless H97/H98 appears and
oven stops.
RESULT
Abnormal
Normal
Abnormal
Normal
Abnormal
Normal = 5V
Still not turn on
RY-2 turns on
Abnormal
Normal
5---5V, 15---5V
Abnormal
Normal
Normal
Abnormal
Normal
Abnormal
0V
0V
Approx. AC 3V
CHECK
Membrane switch continuity
IC-1 pin 31 voltage
IC-1 pin 32 voltage while operation
Short circuit between pin 6 and pin
16 of IC-220
IC-1 pin 38 and pin 39 voltages while
operation at high power
Q220 transistor
Replace display and check operation
Replace IC-1 and check operation
Unplug CN702(2 pin) connector and
measure voltage between terminals
Unplug CN701(3 pin) connector and
measure pin 1 voltage
CAUSE/CORRECTIONS
Membrane switch
IC-1
IC-1
BZ, IC-220
IC-1
➝ Step 2
RY-2
IC-220
IC-1
➝ Step 2
Q220
IC-220, RY-1
DISPLAY
IC-1
IC-1
DISPLAY
DPC
Magnetron
STEP
1
1
1
2
1
2
1
1
1
2
NEW H.V.
TO BE CONTINUED FOR SENSOR MODELS
Steam sensor terminal voltage by
using high impedance tester (20k Ω/
V), when breathe on metal surface of
sensor
Auto sensor cooking does not operate
normally.
(Steam Sensor cooking does not detect
steam from foods.)
Abnormal = 0V
Normal > 10~30mV
Steam sensor
IC-1
1
- 23 -
AC line voltage of 120V
2. DPC/Power Relay
1. Latch Switch
➝ Step 2