Sharp Carousel R-880F Service Manual - Page 12

Browse online or download pdf Service Manual for Microwave Oven Sharp Carousel R-880F. Sharp Carousel R-880F 48 pages. Double grill convection microwave oven
Also for Sharp Carousel R-880F: Service Manual (3 pages)

Print Page

R-880F(S)

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 con-

nection 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.

When all service work is completed and the oven is fully assembled, the microwave power output should be checked

and microwave leakage test should be carried out.

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 proce-

dure letter which will be found in the "Test Procedure"

section.

SERVICING

WARNING TO SERVICE PERSONNEL

TROUBLESHOOTING GUIDE

REMEMBER TO CHECK 4R

1) Reconnect all leads removed from components dur-

ing 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 turntable, close the door

and set the power level to HIGH (100%) and set the

microwave timer for two (2) minutes. And push the start

key. When the two 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.

IMPORTANT: If the oven becomes inoperative because

of a blown fuse F10A in the 1st. latch

switch - 2nd. interlock relay(RY2)- monitor

switch circuit, check the 1st. latch switch,

2nd. interlock relay(RY2) and monitor

switch before replacing the fuse F10A.