4.1. Magnetron

1. Discharge thehigh voltagecapacitor.
2. Remove 1screw holdingair guide A onthe magnetron.
3. Remove 1screw holdingair guide A oncavity topplate.
4. Remove 1screws holdingthermistor on themagnetron.
5. Remove 1 screwholding air guide Aon the wave guide,
then remove the air guide A.
6. Remove 4screws holdingthe magnetron.
NOTE:
After replacement of the magnetron, tighten mounting
screws properly, making sure there is no gap between
the waveguide and the magnetron to prevent
microwave leakage.
CAUTION
When replacing the magnetron, be sure the antenna gasket is in
place.

4.2. Digital programmer circuit

(D.P.C)

CAUTION:
Be sure to ground any static electric charge built up in
your body before handling the DPC.
1. Disconnect connectorCN701 onH.V. Inverter board.
2. Remove 1 screw holding escutcheon base andslide the
escutcheon base upward slightly.
3. Remove all screws holding D.P.C.board on escutcheon
base.
4. Separate D.P.C board from tabs onthe escutcheon base
and remove D.P.C board.
To replace membrane key board
5. Use toolssuch as kinfeetc. to liftthe edge ofescutcheon
sheet and peel off escutcheon sheet & key board
membrane completely from escutcheon base.
NOTE:
1. The membrane key board is attached to the
escutcheon base with double faced adhesive tape.
Therefore, applying hot air such as using a hair
dryer is recommended for smoother removal.
2. When installing the new key board membrane, make
sure that the surface of escutcheon base is clean to
prevent a malfunction or shorted contacts.
4 DISASSEMBLY AND PARTS REPLACEMENTPROCEDURE
10
NN-SD452W/ NN-ST462M / NN-ST452W