– 35 –
Jumper Harness
Retainer
Retainer
VFD Board
4. Check voltage between Smart Board CN10 pins
13 and 14.
• If 5 VDC is present, check the harness
between the Smart Board and VFD. If OK,
replace VFD and Smart Board.
• If 5 VDC is not present, see
Smart Board
,
troubleshooting step 12.
Disassembly
To remove the VFD Board:
1. Disconnect power to the oven.
2. Remove the Control Panel Assembly.
(See
Control Panel Removal
.)
3. Remove the Relay Board.
(See
Relay Board Removal
.)
4. Remove the Smart Board.
(See
Smart Board Removal
.)
5. Remove the 2 Phillips-head screws and remove
the control panel and selector wiring from the
retainer. Slide the VFD Board down from the
retainers.
Note:
When replacing the VFD Board, transfer the
Jumper harness to the replacement VFD Board.
Noise Filter
• Location (See T
op View
.
)
• Helps suppress electromagnetic interference
radiating from the oven and also protects the
microwave from any line noise.
• Supplies
fi
ltered neutral to the Power Supply
Board and Relay Board.
• Contains two 20-amp fuses (WB27x10388).
• Disassembly.
(See
Disassembly
.)
Troubleshooting
1. Disconnect power to the oven.
2. Remove the Grill. (See
Grill
.)
3. Remove the Control Panel Assembly. (See
Control Panel Removal
.)
4. To get better access to components, remove the
wire connected to Noise Filter line out.
5. Reconnect power to the oven.
6. Check voltage between the Noise Filter line out
and neutral out.
• If 120 VAC is present, the Noise Filter is
good.
Note:
If you are troubleshooting L1
not present at the Magnetron TCO, the wire
between the double wire that connects to
RY14 and the Noise Filter neutral out is open.
• If 120 VAC is not present, go to step 7.
7. Disconnect power to the unit. Disconnect Noise
Filter line in and neutral in.
(
Continued Next Page
)