Key Unit Test; Relay Test - Frigidaire GLBM188HB Service Manual

GLBM188HB
[13] KEY UNIT (FPC) TEST
1) Disconnect the power supply cord, and then disassemble
as per "HOOD LOUVER REMOVAL", "REMOVAL OF
OVEN FROM WALL" and "OUTER CASE REMOVAL".
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power trans-
former.
5) Remove the control unit cover.
6) Ensure that these leads remain isolated from other compo-
nents and oven chassis by using insulation tape.
7) After that procedure, re-connect the power supply cord.
8) If the display fails to clear when the Clear Off pad is
depressed, first verify the flat ribbon cable is making good
contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are closed when the door is closed and open when
the door is open. If the door sensing switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the control unit and
make sure the door sensing switch is closed (either close the door or short the door sensing switch connector). Use the Key unit matrix indicated
on the control panel schematic and place a jumper wire between the pins that correspond to the Clear Off pad making momentary contact. If the
control unit responds by clearing with a beep the key unit (FPC) is faulty and must be replaced. If the control unit does not respond, it is faulty and
must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit
or key pad is at fault.
9) Disconnect the power supply cord and then remove outer case.
10)Open the door and block it open.
11)Discharge high voltage capacitor.
12)Remove the control unit cover.
13)Reconnect all leads removed from components during testing.
14)Re-install the covers (outer case cabinet and control unit cover).
15)Reconnect the power supply cord after the covers (outer case cabinet and control unit cover) are installed.
16)Run the oven and check all functions.
[14] N: RELAY TEST
1. Disconnect the power supply cord, and then remove outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power transformer.
5. Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.
6. After that procedure, re-connect the power supply cord.
7. Remove the outer case and check voltage between Pin No. 1 of the 3 pin connector (A) and the oven side terminal of the relay RY1 on the control
unit with an A.C. voltmeter.
The meter should indicate 120 volts, if not check oven circuit.
RY1 and RY2 Relay Test
These relays are operated by D.C. voltage
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated ----------------------------- Defective relay.
DC. voltage not indicated ------------------------ Check diode which is connected to the relay coil. If diode is good, control unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE
RY1
RY2
RY5
RY6
RY7, RY8
RY3
8. If any abnormal condition is defected, replace the control unit.
9. Disconnect the power supply cord and then remove outer case.
10.Open the door and block it open.
11.Discharge high voltage capacitor.
Approx. 24.0V D.C. Oven lamp / Fan motor / Antenna motor
Approx. 24.0V D.C. Power transformer
Approx. 24.0V D.C. Hood motor (HIGH/LOW selection)
Approx. 24.0V D.C. Hood motor
Approx. 24.0V D.C. Cook top lamp (HIGH/LOW selection)
Approx. 24.0V D.C. Turntable motor
G13 G12 G11 G10
Auto
Timer
2 1
Defrost
On-Off
User Keep
3
Pref Wa rm
Sensor
Power
Melt
Level Reheat
Soften
Baked
Vent Light
Potato
Hi/Lo/Off Hi/Lo/Off
7 8
4
CONNECTED COMPONENTS
Page 21
8 – 6
G9 G8 G7 G6
Auto
START
Veggies
Cook
ENTER
Sensor
Popcorn 6 9
Cook
Turn
Snacks
Table 0
Menu
On/Off
STOP
CLEAR
Add
5
30 Sec.
G5
G4
G3
G2
G1