Troubleshooting Guide - Sharp R-1510 Service Manual

CAVITY
THERMAL CUT-OUT
FUSE
20A
A5
B5
HOOD FAN
THERMAL
CUT OUT
B7
GRN
B9
GND
120 V AC.
60 Hz
HOOD
MOTOR
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many
of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which
will be found in the "Test Procedure "section.
IMPORTANT:
If the oven becomes inoperative because of a blown moni-
tor fuse, check the monitor switch, relay (RY1) secondary
interlock relay (RY2), door sensing switch and primary
interlock switch before replacing the monitor fuse. If monitor
fuse is replaced, the monitor switch must also be replaced.
Use part FFS-BA016/KiT as an assembly.
IMPORTANT:
Whenever troubleshooting is performed with the power
supply cord disconnected. It may in, some cases, be neces-
sary to connect the power supply cord after the outer case
has been removed, in this event,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
MAGNETRON
TEMPERATURE FUSE
CONTROL UNIT
RY4
RY6
RY3
High
N.C.
OVEN LAMP
RELAY
Low
RY1
HOOD
RY5
CAPACITOR
N.O.
A1 A3 B1 B3
HOOD
LAMP
HL HL
Figure O-2. Oven Schematic-Cooking Condition

TROUBLESHOOTING GUIDE

N.O.
COM.
E2
DOOR
SENSING
SWITCH
E1
RY2
F1
SECONDARY
INTERLOCK
F2
RELAY
F3
COM.
OL
TTM FM
PRIMARY
INTERLOCK
SWITCH
4. Disconnect the leads to the primary of the power
transformer.
5. Ensure that the leads remain isolated from other
components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power
transformer.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is
installed.
7. Run the oven and check all functions.
7
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME PROGRAMMED.
3. VARIABLE COOKING CONTROL "HIGH".
4. "START" BUTTON PRESSED.
POWER
TRANSFORMER
HIGH VOLTAGE
CAPACITOR
0.94µF/ AC2300V
HIGH VOLTAGE
RECTIFIER
R-1510
R-1511