Smart Board
The Smart Board contains the Power Relay,
Vent Blower Triac, Surface Light Relays and
other load controls. There are three connectors
located on the smart board:
CN3 - Ribbon Connector
CN2 - Door Sensing Switch
CN100 - 120 volt load outputs
Always be certain the capacitor is discharged before
servicing. Mechanically discharge by placing an insulated
handle screw driver between the diode connection of the
capacitor and oven chassis ground.
NOTE:u se screw head close to capacitor to insure ground
metal contact.
WARNING
4000V, RISK OF DEATH
Key Panel
Set Clock - Touch clock pad one time, enter
time of day. Alternately, touch each function pad
and enter time, power level or selected func-
tion. Touch CANCEL/OFF after each function
test to clear. Repeat procedure for each pad.
Control and display should respond to each en-
try. Display should revert to Time-Of-Day after
each cancel. If pads do not respond, clean and
reseat ribbon, perform key panel test to verify
pad operation if needed.
ERROR MESSAGE
Display Signal:
.(<3$'6+257('6(59,&(
MAY BE NEEDED
'HVFULSWLR
n
Keypanel shorted continuously for 60 seconds.
Basic Diagnostics
Dead Unit
Check for power to the microwave
&KHFNLQWHUQDOIXVHDWWKH¿OWHUERDUG
Check for power to the control at CN1 pins 1&3
Check TCOs for open:
Cavity
Thermal
Magnetron
Thermal
Bottom
Thermal
Microwave Runs - No Heat
Check amperage draw on the line wire
< 1 amp
Check Primary Door Switch
Check Control Power Relay
Check HVT Primary Winding Resistance
1 to 5 amps
Open in High Voltage Circuit
Check Magnetron, Capacitor Resistance
and HV Transformer for open circuit
9 to 14 amps, loud hum and fuse blows
Check for shorted capacitor
1 to 5 amps, loud hum, fuse is OK.
Check HV Diode for short
