Sanyo EM-C1900 User manual

PRECAUTIONS
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE
TO EXCESSIVE MICROWAVE ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other micro-
wave source, and make repairs as necessary:
(1)Interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other damage),
(4) damage to or loosening of hinges and latches, (5) evidence of dropping or abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave generating compart-
ments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity, and
connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation and
transmission systems shall be repaired replaced, or adjusted by procedures described in this manual before
the oven is released to the owner.
SERVICE MANUAL Microwave Oven EM-C1900 (U.K)
REFERENCE NO. SM-6310022-00
Pro.Code No. Model No.
437 623 00 EM-C1900UK
Foreword
Read this manual carefully, especially precaution on microwave energy, and follow the procedure
strictly,careless servicing and testing may expose yourself to the microwave energy leakage.

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5.CIRCUIT DIAGRAM
*Caution :The voltage between filament leads of magnetron is about 3.3VA.C, but the filament carries
4KV D.C high voltage with respect to grand. Never touch these lead with bare hand during operation.
Figure 2
㧱㧹㧙㧯㧝㧥㧜㧜

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Check each voltage at connector S104 and S105
after removing each connector (female) from
power circuit board.
Pin No.3 (Ground) and 4,5,1,2 at S105.
Pin No.1 and 2 at S104.
CAUTION:
Proceed with the test only after removing the
wire leads from the primary winding of high
voltage transformer for your safety.
Test procedures:
a) Make sure that the power supply cord is not
plugged in.
b) Remove the connector S104 and S105 from
the power circuit board.
c) Plug the power supply cord.
d) And then, measure each voltage.
COMPONENT
POWER
P.C.B
CONTROL
P.C.B
Measure the voltage: Between test points TP-1, TP-
2 ,TP-3 and ground. (See Figure 12 on page 23)
Note
- Proceed with the check of the control P.C.B to see if
any one of the measured values is different from the
specified values.
CHECKOUT PROCEDURE RESULT
Normal reading:
Connection
Pin No. Voltage
S105
#3 to #4 DC 12V
#3 to #5 DC 16V
#3 to #2 DC 30V
#3 to #1 DC 35V
S104
#1 to #2 AC 2.4V
Test point
TP Voltage
TP-1 DC - 5V
TP-2 DC - 12V
TP-3 DC - 16V
TP-4 DC - 35V
WARNING:
When removing the cabinet, you must disconnect the
power supply cord from the wall outlet for your safety.
Only the checkout procedure below needs the power
supply on. TAKE GREAT CARE to avoid possible shock.
For your safety, proceed with the test only after re-
moving the wire leads from the primary winding of
the high voltage transformer.
Lower
Upper
Primary
winding
Primary
winding