Sharp R-2397 Servicing, Troubleshooting Guide, Warning To Service Personnel, REMEMBER TO CHECK 3D

R-2397

SERVICING

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following parts will result in electrocution.

High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage harness.

REMEMBER TO CHECK 3D

1)Disconnect the supply.

2)Door opened, and wedged open.

3)Discharge high voltage capacitor.

WARNING AGAINST THE CHARGE OF THE

HIGH-VOLTAGE CAPACITOR

The high-voltage capacitor remains charged about 60 seconds after the oven has been switched off. Wait for 60 seconds and then short- circuit the connection of the high-voltage capacitor (that is, of the connecting lead of the high-voltage rectifier) against the chassis with the use of an insulated screwdriver.

Sharp recommend that wherever possible fault-finding 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 3D checks and then disconnect the leads to the primary of the high voltage 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 high voltage transformer.

REMEMBER TO CHECK 4R

1)Reconnect all leads removed from components during testing.

2)Replace the outer case (cabinet).

3)Reconnect the supply.

4)Run the oven. Check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven tray, close the door and press Manual / Repeat key and set the microwave time for one (1) minute. Set the power level to 100% and push the START button. When the one minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out 3D checks and re- examine the connections to 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 leakage test carried out.

TROUBLESHOOTING GUIDE

When troubleshooting the microwave oven, it is helpful to	IMPORTANT: If the oven becomes inoperative because
follow the Sequence of Operation in performing the checks.	of a blown fuse F2 F6.3A in the 1st latch
Many of the possible causes of trouble will require that a	switch - monitor switch - monitor resisitor
specific test be performed. These tests are given a	circuit, check the 1st latch switch, monitor
procedure letter which will be found in the “Test	switch and monitor resistor before re-
Procedure”section.	placing the fuse F6.3A.

7