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Magnetron
•
Location (See
Right Side View
.)
• Filament resistance less than 1
Ω
.
• The Magnetron converts the high voltage
supplied by the transformer, capacitor,
and diode into radio frequency waves of
electromagnetic cooking energy.
• WARNING:
Always be certain the capacitor
is discharged before servicing. (See
Capacitor
and Diode
.
) Use electrician's discharge pliers
and electrician's gloves under Kevlar gloves (or
equivalent protective gloves) when discharging
the capacitor.
• Note:
The capacitor has an internal discharge
resistor that automatically discharges the
capacitor when the oven turns off. Under normal
operation, the capacitor should fully discharge
within 30 seconds.
• For operating algorithms, see High Voltage in
the
Load Algorithm Chart
.
• Disassembly.
(See
Disassembly
.)
Troubleshooting
1. Does the display operate properly?
• If no, see
VFD Board
, troubleshooting step 1.
• If yes, go to step 2.
2. Is Magnetron staying on all the time or not
coming on?
• If Magnetron is staying on, go to step 8.
• If Magnetron is not coming on, go to step 3.
3. Pivot the Control Panel Assembly out from the
oven. (See
Control Panel
.)
4. To gain better access to components, remove
the wires that plug into the large relays on the
Relay Board.
(See
Relay Board
.)
Cut the wire tie
that the Smart Board CN103 wire harness (See
Smart Board
.) is routed through.
5. Set oven to Microwave for 2 minutes. (See
Operating Modes
for set up instructions.)
6. Start Microwave cycle. While unit is running,
check resistance between the 2 terminals on
Relay Board RY14.
Note:
This step requires
checking resistance of relay contacts while the
unit is running. The high voltage relay wires
(RY14) must
not be
connected to the relay when
making this check.
• If resistance is in
fi
nite, the high voltage
relay is not closing. (See
Relay Board
,
troubleshooting section.)
• If resistance is approximately 0
Ω
, go to step 7.
7. Check voltage between the primary leads of the
High Voltage Transformer.
• If 120 VAC is present, problem is with one
or more of the high-voltage components.
Check resistance of the magnetron
fi
lament. If OK,
see
High Voltage Transformer
,
troubleshooting section,
see
Capacitor and
Diode
,
troubleshooting section.
• If 120 VAC is not present, see
Primary
Interlock Switch
,
troubleshooting step 4.
8. Disconnect Relay Board RY14. Is the Magnetron
staying on?
• If the Magnetron turns off, the magnetron
relay is stuck closed. (See
Relay Board
,
troubleshooting section.)
• If Magnetron stays on, the single wire in the
connector that connects to RY14 is shorted
to ground.
(
Continued Next Page
)
