Touch Control Panel Assembly - Sharp R-9360 Service Manual

TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
F
(CONT'D)
POWER TRANSFORMER
SECONDARY
INTERLOCK
G BLOWN FUSE
If the fuse in the upper-monitor switch circuit is blown when the door is opened, check the upper latch switch
and monitor switch according to the Test Procedure of those switches, before replacing the blown fuse.
if the monitor fuse is blown by improper switch operation, adjust or replace the defective switch and fuse
at the same time.
Replace just the fuse if the switches operate normally.
CAUTION; REPLACE BLOWN 10A FUSE, PART NO. QFS-CQOOIYBEO.
H TEMP. FUSE TEST
A continuity check across the temp. fuse terminals should indicate a closed circuit.
If the temperature of the magnetron reaches 115OC, the temp. fuse opens. If the temp. fuse has opened,
replace the fuse. An open temp. fuse indicates overheating of the magnetron assembly. Check for restricted
air flow to the magnetron through the opening in the chassis, especially the cooling duct.
I TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, un-
like conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and
ohmmeter. In this service manual, the touch control panel assembly is divided into two units; key and con-
trol units and troubleshooting by unit replacement is described according to the symptoms indicated.
1. Key Unit.
The following symptoms indicate a defective key unit. Replace the key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
2. Control Unit
The following symptoms indicate a defective control unit. Replace the control unit.
2-l In connection with pads
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
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