TROUBLESHOOTING CHART
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current. contact with any part of the
high voltage circuit will result in electrocution.
REMEMBER TO CHECK z
REMEMBER TO CHECK*
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.
j WARNING AGAINST THE CHARGE OF ThE
I
HIGH-VOLTAGE CAPACITOR
The high-voltage capacitor remains charged
about 80 seconds after the oven has been
switched off. Wait for 60 seconds and then short-
circuit the connection of the high-voitage capaci-
tor (that is, of the connecting lead of the hgh-voit-
age rectifier) against the chassis with the use of
an insulated screwdriver.
Sharp recommend that wherever possible fauit-iind-
ing is carried out with the supply disconnected. It
may in, some cases, be necessary to connect the
supply after the outer case has been removed. in
this event carry out 3lJ checks and then disconnect
the leads to the primary of the power transformer.
Ensure that these leads remain isolated from other
components and the.oven chassis. (Use insulation
tape if necessary.) When the testing is completed
carry out 3D checks and reconnect the leads to the
primary of the power transformer.
1) Reconnect all leads removed from components during
testing.
2) Replace the outer case $abinet).
3) Reconnect the supply.
4) Run the oven. Check a!1 functions.
Microwave ovens shouid not be run empty. To test icr the
presence of microwave energy within a cavrty. $ace a
cup of cold water on the oven turntable, ciose rhe dcsr
and set the microwave timer for two ;2j minutes. Se! the
power ievel to HIGH and push the STAET ~ttzn. ‘lWe~
the two minutes has elapsed (timer at zero,
:zrciiii;,;
check that the water is new hot. If the water :emair:s Izsic
carry out 3D checks and ye-examine the c~~r~;:rlec:ic~s is
the component being tested.
When all service work is completed, and the oven is fully assembled, the microwave power output should be
checked and microwave reakage test carried out
TROUBLESHOOTING GUIDE
When troubleshooting the microwave ovenit is helpful
to follow the Sequence of Operation in performing the
IMPORTANT:If the oven becomes inoperative because of a
checks. Many of the possible causes of trouble will re-
blown fuse M8A in the right latch switch - left
quire that aspecific test be performed. These tests are
latch switch - monitor switch - monitor resisitor
given a procedure letter which will be found in the “Test
circuit check the right latch switch. left latch
Procedure”section.
switch, monitor switch and monitor resistor
before replacing the fuse M8A..
11
To Next Page
Loading...
Need help?
General
