Oven Sensor And Door Lock Switch; Special Functions; Thermal Switch; Oven Calibration - GE JGS968 Service Manual

OVEN SENSOR AND DOOR LOCK SWITCH

MOTORIZED DOOR LOCK
The motorized door lock assembly is located above the oven. The assembly consists of a lock motor
cam and switch assembly, lock hook and mounting plate.
MOTORIZED DOOR LOCK OPERATION
The lock motor is energized when the control is set for Clean and Clean Time is selected. The K4
Relay contacts will close and complete the circuit that supplies the voltage to the lock motor.
NOTE: Control display will flash "LOCK DOOR"
UNLOCKED
if the door switch is in the "C" to "NC" position
LOCK SW. CIRCUIT SENSOR AND LOCK
SWITCH CONNECTORS
(door open).
LOCK SW. #1
8
• The words "LOCK DOOR" will flash on and off
in the display while the lock motor is in motion.
LOCK
SW. #2

THERMAL SWITCH

6
DOOR LATCH OUTPUT PIN 5, -25V DC When the door is locked, the words "LOCKED
5
4 DOOR LATCHED INPUT PIN
DOOR" remain illuminated in the display.
DOOR UNLATCHED INPUT PIN
3
• CAM – The cam on the motor performs two
LOCKED functions:
LOCK SW. CIRCUIT 1. Positions the lock hook in the door to
SENSOR AND LOCK
SWITCH CONNECTORS
LOCK SW. #2
prevent opening during clean operation.
8
2. Operates the lock switches which tell the
LOCK control if the door is unlocked or locked
THERMAL SWITCH 6
SW. #1
5 DOOR LATCH OUTPUT PIN 5, -25V DC and ready for Clean operation.
4 DOOR LATCHED INPUT PIN
3 DOOR UNLATCHED INPUT PIN
UNLOCKED LOCKED
NOTE: When door is either
UNLOCK SW. UNLOCK SW.
being locked or unlocked,
N.O. CONTACT N.O. CONTACT
CLOSED OPEN
both lock switches will be in
the open position.
CAM IN
LOCK SW.
UNLOCK POSITION
N.O. CONTACT
OPEN

SPECIAL FUNCTIONS

The control has a section that can be entered to change how the control will work. To enter this section:
Press and hold BAKE and BROIL pads for 2 (two) seconds and "SF" appears in the display. Select
the area to change. When the change has been made, press START to return to Time of Day.
• End-of-Cycle Tone – Press TIMER pad. Display shows "Con Beep" when control is set for
continuous End-of-Cycle Tone or "Beep" when set for noncontinuous.
• °F or °C – Press BROIL pad. Display will show either "F°" or "C°." Press BROIL pad again to
change.
• 12-Hour, 24-Hour or blank out Time-of-Day Clock – Press CLOCK pad. Display will show
"12 hr," "24 hr," "OFF" for blank clock. Press again to change.
• 12-Hour Shutdown comes set to shut down after 12 hours of continuous operation; this can be
eliminated—press DELAY START pad. Display will show "No Shdn." To turn back on, press
DELAY START pad again and display will show "12 Shdn."
• Sales Mode (special feature for sales floor demonstration) – Press CLOCK and TIMER pads
at the same time. Display will start to cycle through the different modes of operation.
• Sabbath Mode – This feature disables all but Bake and Timed Bake, overrides 12-Hour
Shutdown, disables beeps and puts symbols in the display during Bake. Access by pressing
DELAY START pad until display shows "SabbAtH." Exit by pressing DELAY START until
"No Shdn" or "12 Shdn" shows.
THERMAL SWITCH
The thermal switch is located on the floor of the component compartment in front of the fan
motor. The thermal switch is wired in series with the lock motor switches. The limit switch
opens at 275°F and closes when temperatures cool below 205°F. If the thermal switch opens during:
1. Oven Temperature Below 600°F, program is cancelled when thermal switch opens. Lock motor
will run and the words "LOCK" and "DOOR" will be flashing in the display.
2. Oven Temperature Above 600°F, any mode of operation control will go to -F2- failure code. When
this condition exists, check the fan operation (look for obstructions), inspect oven installation
(make sure grille areas are not blocked), oven insulation and lock circuit.

OVEN CALIBRATION

Testing has shown that this oven has the best cooking performance at a control setting of 350°F
when the AVERAGE center oven temperature is between 350°F and 390°F. Customers may change
the average center oven temperature by ± 35°F to satisfy their own cooking needs.
To change:
• Press and hold BAKE and BROIL pads until "SF" appears in display.
• Press BAKE pad to enter oven calibration mode. "00" appears if oven calibration has not
been changed previously. If oven calibration has been changed previously, a temperature
between ± 35°F will be displayed.
• Use number pads to change average oven temperature. (Use BAKE to switch between + or -
settings.)
• Press START pad to return to Time of Day.
ERC FAILURE CODES
The oven may stop operating but not give an F code on the display immediately. F codes are stored
in nonvolatile eeprom memory until the same fault occurs twice consecutively. F codes can be
recalled by pressing together TIMER, CLOCK and 9. While F codes are displayed, pressing 8 and 6
together will clear them. A fault must exist continuously for 5 minutes before an F code is recorded
(F2 and F8 are sooner).
FAILURE
CODE MEANING CORRECTION
-F0-
Shorted OFF key Perform glass touch board key panel test.
(Membrane) or GT Error
229C4059P613
FAILURE
CODE MEANING CORRECTION
-F2-
Over temperature • Welded relay contacts
1. Inside oven cavity as • Cooling fan stalled or blocked
measured by sensor • Airflow to rear of unit
over 650°F unlatched • High resistance in oven sensor leads/connectors
or 915°F latched (especially at sensor in rear)
-F3- Open oven sensor (under • Disconnect power. Disconnect sensor harness from
950 ohms)
control. Measure sensor resistance (white leads) to
be ~1080 ohms at room temperature with 2 ohms
per degree change.
• Look for damaged harness terminals if not a bad
sensor.
-F4- Shorted oven sensor • Disconnect power. Disconnect sensor harness from
(over 2900 ohms) control. Measure sensor resistance (white leads) to
be ~1080 ohms at room temperature with 2 ohms
per degree change.
• Separate sensor from harness to determine fault.
Determine if problem is with key panel or control by
-F7- Shorted matrix or START
disconnecting ribbon cable and measuring flat cable
key
using pinout chart. Allow up to 1000 ohms when
pressing a key.
-F8- EEPROM data shift failure If repeated, replace control.
-F9- Cooling fan stalls while Cooling fan or airflow to control area.
CAM IN above 650°F; open
LOCK POSITION
thermal switch in yellow
leads
LOCK SW.
N.O. CONTACT
CLOSED -FC- Loss of latch motor safety Replace control.
circuit
COLD START ODOR ADJUSTMENTS
NOTE: A small amount of odor is normal and will be present when the range is first turned on.
Also, adjustments require disassembly of the burner section. To prevent handling hot parts,
oven should be cool.
STEP 1: Remove oven door, oven bottom,
OVEN BOTTOM
flame spreader (burner baffle), orifice
cover and oven burner. See below.
STEP 2: Closely Examine the Angle of
the Orifice. The orifice must point straight
into the burner. Check the angle by
looking at the orifice from above and from
the front. A socket Head Nut Driver may
be placed over the maintop orifice to help
determine any out of alignment condition.
The angle can be corrected by using a
small adjustment wrench clamped loosely
over the orifice to bend the orifice and its
mounting assembly as needed. See below.
STEP 3: Inspect the Primary Air Opening. The opening must be clear and free of insulation
all the way down to the metal shield below (0.314 inch opening). See above.
STEP 4: Using a drill bit as a gauge, adjust the air shutter opening.
COLD START ODOR ADJUSTMENTS
STEP 5: Examine the orifice cover. The cover must be as air-tight as possible. Bend the cover
to close off gaps between the sides and the top of the cover.
STEP 6: Install the oven door and observe the burner flame. Before installing the flame spreader
and oven bottom, close the oven door, set the control for BAKE and observe the burner flame.
Note: The door should remain closed during this test.
Observe the flames for a period of at least 2
minutes. The flame should not "lift or blow off" the
burner during any period of operation. It should be
1/2" To 3/4"
blue with approximately a 1/2" to 3/4" inner cone.
LP Gas Installations: If flames lift off the burner
and appear unstable, reduce the air shutter
openings an additional 1/32", cool range and repeat
Step 6 from a cold start. If flames are too large but
appear stable, check to be sure the range was
properly converted.
Natural Gas Installations: If flames are too large
but appear stable, tighten the orifice hood to reduce
the gas flow to the burner.
STEP 7: Examine Flame Spreader for signs of warpage. If warped, spreader will have to be
replaced.
STEP 8: Install Flame Spreader and Oven Bottom. With customer present, test range from a cold
start to be sure odor problem has been corrected.
SELF-CLEAN & MOTORIZED DOOR LOCK
OPERATION LOCK CIRCUITS
There are two circuits controlling the locking and unlocking of the door. These are the lock motor
circuit and the lock switch circuit.
The lock motor circuit applies voltage (120 VAC) to the lock motor. This circuit is from L, through
the door switch, lock relay, lock motor to neutral. For this circuit to be complete, the lock relay must
be energized by the (HP) control and the door must be closed. An open oven door results in "LOCK
DOOR" flashing in the display after the control has been programmed for clean and "START" has
been depressed.
The lock switch circuit "tells" the control if the lock motor is in the unlocked or locked position or
somewhere in between. There are two lock switches mounted to and operated by the lock motor.
The lock switch circuit is from the (HP) control, through one of the lock switches (switch 2 for
unlocked or switch 1 for locked) back to the (HP) control. If neither switch is closed, and the oven
temperature is below 600 degrees, the (HP) control will energize the lock motor circuit until the
correct switch closes to complete the circuit. (If circuit to the correct switch is open, lock motor will
run continuously with the oven below 600 degrees.)
CLEAN CYCLE AND LOCK SEQUENCE
1. Program the Clean Cycle:
• Press "SELF-CLEAN" pad. 4 hours (4:00)‚ appears on the time display. (Cleaning time can
be changed from the 4-hour starting point by pressing the "SELF-CLEAN" pad a second time.
• After "START" has been pressed, the word "ON" illuminates in red to indicate the cycle
has begun.
2. Locking the Door:
• After programming the clean cycle and pressing START pad, the control energizes the lock
relay. Voltage (120 VAC) is applied to the lock motor circuit. Oven door must be closed before
lock motor can run. "LOCK DOOR" will flash and control will beep until the door is closed.
• The lock motor begins to revolve and turns a cam mounted to the motor shaft.
• The words "LOCKED DOOR" will flash on and off on the display while the lock motor
is in motion.
• As the cam revolves about 1/2 revolution (approximately 12 seconds), it has moved the
lock "hook" into a corresponding slot in the oven door which secures the door.
• The movement of the cam has also closed lock switch 1 which
"tells" the control the door is locked. The control then removes
power from the lock motor circuit by de-energizing the lock
relay.
• The lock motor stops and lock switch 1 is held closed by the
cam through the clean cycle.
• The words "LOCKED DOOR" stop flashing and remain
illuminated in the display.
FLAME
• The word "ON" illuminates in the display.
SPREADER
3. During the Clean Cycle:
• The BROIL relay closes (audible "click") and the broil burner begins to heat. The broil burner only
ORIFICE COVER will operate during the first 30 minutes of the clean cycle followed by the bake burner only during
the remaining time.
• As the clean cycle progresses and the temperature of the oven control area rises, the cooling fan
BURNER
is activated.
• A normally closed thermal switch is mounted on a bracket in front of the cooling fan. This switch
is in the lock switch circuit and will open the lock switch circuit in the event of an over-temperature
condition in the control area (caused by a stalled fan, fan switch failure or similar condition).
An -F2- (over-temperature) failure code will appear on the control if this switch opens while the
oven is above 600 degrees. With the oven between 400 to 600 degrees, the clean cycle will be
cancelled by the opening of the switch and the control will revert back to the time-of-day mode.
Below 400 degrees, the lock motor will revolve continuously and the words "LOCKED DOOR"
will flash on the control until the circuit is reestablished.
• The oven will cycle to maintain an average clean temperature of 830°F.
CONVECTION FAN ASSEMBLY
The convection fan assembly is located on the back
wall of the oven liner behind the panel with the screen
in the center.
Inner Cone of Flame
• Remove 4 screws mounting panel
(2 on each side) and pull forward.
TO SERVICE FAN:
Oven Broiler
Fan blade can be replaced from inside
Burner
oven. Oven must be removed from
installation to access convection fan motor.
STORAGE DRAWER REMOVAL
TO REMOVE:
1. Pull the drawer out until it stops.
2. Lift the front of the drawer until the stops
clear the guides.
3. Remove the drawer.
TO REPLACE:
1. Place the drawer rail on
the guides.
2. Push the drawer in until
it stops.
3. Lift the front of the
drawer and push in until
the stops clear the
guides.
4. Lower the front of the
drawer and push in until
it closes.
The oven uses a fan for cooling the components. Air is pulled in by the fan blades and circulated in
the component compartment. The air is exhausted through louvers below the control panel and out
the slots above the door.
DOOR ASSEMBLIES:
The doors can be separated into two assemblies: (1) Outer assembly which consists of handle, vent
trim, outer glass, bottom trim and frame; (2) Inner assembly which consists of inner panel, gasket,
glass panels and insulation. The assemblies are held together by 2 screws on each side, along with
4 screws across the bottom.
CAUTION: Care must be taken when mounting door handle not to overtighten handle screws.
Overtightening screws can damage handle. Hand-tighten screws (do not use electric driver).
Make sure handle fits snuggly to door panel.
SELF-CLEAN DOOR GASKET: The door gasket is attached to the inner door panel by a chain of
spring clips.
1. Locate spring clip at center of gasket and insert in hole on inner door panel near top.
2. Install gasket by bending at 90° beside clip and rocking into hole.
3. Tuck loose ends into slot at the bottom of inner panel.
LOCKED
UNLOCK SW.
N.O. CONTACT
OPEN
CAM IN
LOCK POSITION
LOCK SW.
N.O. CONTACT
CLOSED
CONV.
OUTER
FAN
BACK
MTG.
PANEL
SCREWS
OVEN
(3)
INSULATION
OVEN
CONV.
LINER
FAN
FAN
SUPPORT
BLADE NUT
OVEN
CAVITY
SCREWS
(4)
FAN
MOUNTING
BLADE SCREWS
(3)
RAIL
STOP
GUIDE
STOP
——— If Drawer Won't Close ———
Drawer front panel tipped
Drawer does not close completely
away from body side
NOTE: RY references on control may be different than shown.
Rear drawer support
Power cord may be
is resting on top of
obstructing drawer
guide rail
in this area
——— If Drawer is Crooked ———
Drawer front panel tipped to one side
Rear drawer support
on top of guide rail
on the high side
REMOVABLE OVEN DOOR
COMPONENT COMPARTMENT AIRFLOW