How To Test Control Board On Refrigerator

Key Points

Step-by-step instructions on how to troubleshoot and replace a GE Refrigerator chief control board
Instructions on installing Part # WR55X10956 and WR55X11064

Applicative Models
Location
Maintenance – Visual Inspection Tips
Input / Output Specs

Applicative Models

GE Model	Part #	Name	Replaces
PFCF1NFW (PFCF1NFWAWW PFCF1NFWABB PFCF1NFWASS)	WR55X10956 (Check here for the latest availability and cost)	Chief Control Lath Assembly (computer logic lath)	1550509, AH2371144, EA2371144, PS2371144, WR55X10657, WR55X10658, WR55X10662, WR55X10697, WR55X10745, WR55X10774, WR55X10929, WR55X10943, WR55X10958
PFCS1NFW	Run into PFCF1NFW	Main Command Board	Run into PFCF1NFW
PFIC1NFW	Come across PFCF1NFW	Principal Control Board	See PFCF1NFW
PDCF1NBW	See PFCF1NFW	Chief Control Board	See PFCF1NFW
PFCF1NFC	WR55X11064 **	Main Control Board	WR55X10697
PFCF1NFX	WR55X11064 **	Main Command Board	See PFCF1NBW
PFCF1NFYA	WR55X11064 **	Main Control Lath	Meet PFCF1NBW
PFCF1NFZ	WR55X11064 **	Main Control Board	See PFCF1NBW
PFCF1NJW (PFCF1NJWABB, PFCF1NJWACC, PFCF1NJWAWW)		Main Control Lath	Come across PFCF1NBW

** Y'all may see a sticker on the backside of your refrigerator that states "ATTENTION: Utilise Simply MAIN Board SPECIFIC VARIABLE SPEED COMPRESSOR. REPLACEMENT Part NUMBER WR55Xxxxx". Please notation that all role numbers listed in the above table are the latest data obtained direct from GE Apparatus Parts.

Location

Main control board is merely accessible via rear panel of your refrigerator.

Model PFCF1NFW chief command board is located on the lower correct side. Your specific location may vary.

Please notation that the black duct tape yous encounter on the top side of a cover panel was applied by me to prevent any liquid from getting inside the main control surface area.

Principal Control Board

Show below is the a WR55X10956 lath. Depending on your refrigerator model, it might look slightly different.

With cables – WR55X10956
Without cables – WR55X10956

Input / Output Specifications

The principal command board is divided into two sections: Depression voltage DC side (right one-half) and 120VAC side (left one-half that contains two large capacitors). The sides are on entirely two different circuits (the reason for having ii separate greenish basis wires).

Low Voltage Side

Jumper	Pin	Description
J1 (Sensor Input)	1	FF Thermistor
	2	Ambience Thermistor
	iii	FZ Thermistor
	4	FZ Evap. Thermistor
	5	Thermistor Common +5V
	6	Not Used
	vii	Not Used
	viii	Model Selector
	9	Model Selector
J2 (Fan Speed Control)	one	Evaporator Fan (RPM, Tachometer)
	2	Model Selector
	3	Fan Common
	4	Evaporator Fan
	5	Condenser Fan
	6	Mullion Bat Heater
	7	N/A (Custom Cool Fan on certain models)
	viii	Fan +12V
J3	1	Damper
	ii	Damper
	3	Damper
	four	Damper
	5	N/A (not used in PFCF1NFW model)
	6	N/A (not used in PFCF1NFW model;3 Way valve -Dual Evap)
	seven	N/A (non used in PFCF1NFW model;3 Way valve – Dual Evap)
	8	N/A (not used in PFCF1NFW model;3 Way valve – Dual Evap)
	9	N/A (non used in PFCF1NFW model;iii Fashion valve – Dual Evap)
	x	Northward/A (not used in PFCF1NFW model;3 Way valve – Dual Evap)
J4 (Communications)	one	Advice ii Style Digital
	2	Communication +12V
	3	Communication Mutual
	four	Not used
	5	Non used
J5 (Not Used in PFCF1NFW)	i	North/A (Custom Cool models only; QC Damper 1+)
	2	North/A (Custom Cool models only; QC Damper 1-)
	three	N/A (Custom Absurd models only; QC Damper 2+)
	4	N/A (Custom Cool models only; QC Damper 2-)
	v	+v VDC
	6	TC Thermistor (Quick Chill model merely)
J13 (Earth)	i	Basis
J15 (Inverter)	ane	Inverter Output (4-6 VDC)
	two	Inverter Common
EF-1 (Evaporator Fan)	Northward/A	Resistors (will fire out if the evaporator fan is shorted out)

High Voltage side

Jumper	Pin	Description
J7	ane	Non used
	2	Not used
	3	Dispenser Water Valve
	4	Not used
	v	N/A (models w/ Quick Chill Heater)
	6	FF Light switch
	7	FZ Light switch
	8	Not used
	ix	Neutral
J8	1	Not used (supply power to compressor on certain models; PFCF1NFW uses inverter)
J9	1	Defrost Heater
J11	ane	L1 or Line 1 power supply
J12	1	Mullion heater
J18	1	Ice maker water valve heater

You lot should perform periodic visual inspection of your board (top and lesser sides). A healthy board should wait something like this:

What your looking for during your visual inspection is to detect whatsoever signs of burnt components.

xxxx Some burnt components may simply be visible from the underside so you volition have to unplug your refrigerator and disconnect all wires and remove the board for closer inspection.

Primary Board Tests

Measuring thermistor resistance at J1 jumper
Measuring thermistor voltage at J1 jumper

Required Tools / Materials

iii/8″ socket
Needles nose pliers
Multi-meter
Ziploc bags
Ice
Gyre of Duct tape
2″ zip ties
4 thermistors
1 defrost heater temperature sensor

J1 Jumper

By the terminate of this section, nosotros want to confirm that J1 on the main board and all thermistors are in working society

Verify that thermistor resistance is +/- 5% of sixteen.three K ohms or sixteen,300 Ohms at simulated 32 degrees
Verify the main board J1/Pin5 is sending +5 VDC to thermistors (warning – if you are not careful, you may damage your board!)
Verify that each thermistor is returning 2.8 to 3.5 VDC (depending on the temperature) (alert – if yous are non careful, y'all may harm your board!)

Evaporator Thermistor and Defrost Temperature Sensor

These two parts are tucked away in a very tight infinite in the freezer so it is almost incommunicable to test them in place.

My recommendation it to examination and verify that all other thermistors are in working order and that the main control board is sending a proper voltage.

Only then, skip the testing and Supercede these ii parts. At around $fifteen a piece, they are not too expensive and you will save time and lots of frustration.

Preparation Work

Step # A1 – Fill up 3 pocket-size nix-loc bags with water ice and some h2o and set them aside for ff, fz and ambient thermistors (Pin 4 – evaporator thermistor will be replaced so it will not be tested)
Footstep # A2 – Pull out the refrigerator and unplug information technology
Footstep # A3 – Remove the bottom freezer door
Footstep # A4 – For the fridge and/or freezer thermistors, remove the plastic shark gill covers by inserting a small-scale flat caput screwdriver from the bottom and popping information technology off; thermistor wire tin be pulled out almost two inches
Pace # A5 – For the ambient thermistor, remove the toe kicking plate (below the freezer door) by removing 2 Phillips screws; you lot will need to cut off the zip tie
Footstep # A6 – Dunk each thermistor into a ziploc bag and tape it securely to the refrigerator so that the bag volition not spill; wait 5 min
Footstep # A7 – Uncover the primary control board access panel using a 3/8″ socket
Step # A8 – Affect bare metal surface (abroad from the principal control board area) to discharge whatever static electricity

Measuring Thermistor – Resistance

Taking a resistance measurement with wires attached to the main board volition produce inaccurate results.

Step # B1 – Set the multi-meter to "ohm"
Step # B2 – Detach J1 wire harness block from the chief command lath
Step # B3 – Insert the black lead into Pin one (FF thermistor) on the wire harness cake (non the master command board pin!); nosotros are not testing polarity and so it does not matter which atomic number 82 colour goes where;
Step # B4 – Insert the red lead into Pivot 5 (mutual) on the wire harness block (again, non the chief control lath pin!)
Step # B5 – Your resistance reading should be effectually xvi.3 K-ohm or sixteen,300 ohm
Step # B6 – Repeat steps #B3 and B4 for Pins 2 and iii;all thermistors are identical and then the return resistance value should be very shut to each other;
Footstep # B7 – If the return resistance value is way off, you can either do additional testing with the fridge plugged in (i.due east. alive voltage) or merely supersede the faulty thermistor

Warning

Although this test section involves working with the depression voltage side, you tin impairment the board, hurt or even impale yourself if you accidentally touch a wrong part! If you are uncertain of your capabilities, please consult a apparatus technician.

Measuring Thermistor – Voltage

Taking resistance measurements with wires attached to the chief board will produce inaccurate results.

Footstep # C1 – Set the multi-meter to "VDC"
Step # C2 – Leave the J1 wire harness block fastened to the main control board
Step # C3 – Insert the black pb into Pivot 1 (FF thermistor) from the top side on the wire harness cake
Step # C4 – Insert the ruddy lead into Pin5 from the top side on the wire harness cake
Stride # C5 – Your return voltage reading should between 2.eight to iii.five VDC
Step # C6 – Repeat steps #C3-four for Pins 2-iv; all thermistors are identical so the render resistance value should be very shut to each other
Stride # C7 – If the return voltage value is fashion off, replace the faulty thermistor