Page 62 Part # MCOSM06 Rev 1 (11/03/08)
"HELP" cavity in excess of 560Deg. F
"Door" 1 of 2 door switches has opened -which one?
"oPEn" prompt for operator to open door during cool down.
"Prob" The controller cannot read the probe. Check to verify
the probe is connected, if connected ohm the probe out
- see temperature readings.
"Setb" The controller is in setback. This will happen if the
setback key is pressed or if setback is active and there as
been a non-usage time key. Setback is not active in a cook.
Press setback to cancel setbacks.
Keypad Fault Does not apply to 200 series.
If the oven will not turn on when the On/O button is pressed
check to verify that the connection to the keypad connector is
properly attached to the control board.
If the connector is attached the keypad is defective.
No Sound Fault Does not apply to 200 and 300 series
If the oven operates normally but the sound is dierent,
adjust the piezo so that it is not touching any other
component. If the oven operates properly but there is no
sound, the piezo is defective and replace the control board.
Door Switch Fault Does not apply to 200 series.
If Cool down, the fans continuing to work when the door is
opened, or the oven does not heat check the door switches.
Upper door switch for HEAT, Lower door switch for COOL.
Fan Fault Does not apply to 200 series.
If the fan does not operate check the door switches, and the
LEDs on the relay board. On the relay board next to the low
and high fan relay is an LED that is lit when the fan is engaged
(CR3 LED for high and CR4 for low speed). The controller will
call for either low or high fan at all times. The pulse fan is the
low fan speed that will pulse on for 30 seconds, o for 30
seconds. The heat will always be o when the fan is in the
o cycle. If the control is calling for a fan speed and neither
fan LED is lit, check the harness and the pins in the harness
to verify that neither has been pushed out of it's connector.
Check the motor or the fan if the rest of the system seems
operating satisfactory.
No Heat Does not apply to 200 series.
If the oven does not heat check the door switches, the set
temperature and the LED on the relay board. On the relay
board next to the heat relay is an LED that is lit when the relay
is engaged. If the controller is calling for heat and the, heat
LED is not lit, check the harness and the pins in the harness
to ensure that neither has been pushed out of it's connector.
Check the contactor or gas valve if the rest of the system
seems operating satisfactory.
Potentiometer Or Encoder FaultPotentiometer- 200 and 300 series. The potentiometer can
turn 3/4 of a complete rotation. If the temperature does
not change when the potentiometer is turned, (this will
take 5 minutes or more) check to see if the potentiometer is
connected to the control board. Pot is a 0 to 10.25K ohm.
If the oven only maintains one temperature and the
potentiometer is connected the potentiometer is defective.
Encoder series 410,450,455,470,471 and 475 series. The
encoder can turn indenitely. If the temperature display
does not change when the encoder is turned, check to see if
the encoder is connected to the control board. If the display
does not change when a manual temperature is entered the
encoder is defective.
Core Probe Failures Applies to 455 only.
If the core probe is used, the core probe LED will be lit and the
temperature of the product will be displayed if the product is
above 32°F. The programmed range for the core probe is 100
to 200 °F.
Temperature ReadingsRoom Temperature: 77 °F = 1000 ohms
100°F =1103 ohms
200°F =1350 ohms
300°F =1554 ohms
350°F =1654 ohms
400°F =1753 ohms