Sharp R-1880LS Service Manual page 20

R-1880LS/LST
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.
TEST PROCEDURE
CONDITION
Home fuse blows when power cord is plugged into wall receptacle.
Monitor fuse blows when power cord is plugged into wall receptacle.
Display does not illuminate when power cord is first plugged into wall receptacle.
Display does not operate properly when STOP/CLEAR key is touched. (The time of
day should appear on the display with beep sound during normal condition.)
OFF
CONDITION Oven lamp does not light with door is opened.
Hood fan motor operates when power cord is first plugged into wall receptacle.
Temperature of oven base seems more than 140
range below. But hood fan motor does not turn on automatically. (Normally, food fan
motor should be operating at low speed.)
Hood lights do not turn on with pushed Light button.
Hood fan motor does not rotate at all with pushed Vent button.
Speed of the hood fan motor does not change when the Vent button is touched for
IDLE
this function.
CONDITION
Oven lamp does not light in cook cycle. (But it does light when door is opened.)
Fan motor does not operate. (Oven lamp and turntable motor operate.)
Turntable motor does not operate (Oven lamp lights and fan motor operate.)
COOKING
CONDITION
Cooking cycle runs 1 minute then shuts down.
(COMMON)
Oven does not go into cook cycle when START pad is touched
Oven seems to be operating but little or no heat is produced in oven load. (Food in-
completely cooked or not cooked at all at end of cook cycle.)
Oven goes into a cook cycle but extremely uneven heating is produced in oven load
(food).
Variable cooking does not operate properly except Cooking Power 10 (P-HI) mode.
MICROWAVE
COOKING
Function of TIMED DEFROST does not operate properly.
CONDITION
Stirrer motor does not operate. (Other parts operate.)
CONV indicator lights, but oven does not go into cook cycle when START pad is
touched.
CONV indicator lights, but heating element does not heat.
Temperature in the oven cavity is lower or higher than preset.
Convection motor does not operate.
CONVECTION
COOKING
Convection cycle runs 4 minutes and 15 seconds then shuts down.
CONDITION
The oven stops and "ERROR" is displayed or does not end during Sensor Cooking con-
dition. (Oven does not shuts off after a cup of water is boiling by Sensor Cooking.)
Oven stops at 3 seconds after starting.
SENSOR
COOKING
CONDITION
TROUBLESHOOTING GUIDE
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
PROBLEM
ο ο
F (60 C) because of operation of the
0
CK = Check / RE = Replace
A B C D E F G H I J K L