These are the checks to make for no display on most F/L LG washers....
Sorry there are no short cuts
After confirming correct supply voltage at the receptacle:
1). Remove the top of the washer by removing (2) screws from the rear of
the top panel and sliding the panel toward the back and lift off. Make sure
the washer is plugged in and locate the Main PCB in the back left corner of
2). First press the Power Button, then look through the slots of the Main
PCB Cover and see if the (Red LED) is lit.
3). IF the Red LED is lit; this tells you the Power Button is good, there is 120
VAC to the Main PCB, and the microprocessor is working. Go to Step 7. IF
the Red LED is not lit; you will need to locate the Power Button connector
it has a Red, Yellow, and Black wire in the connector;
so that you can test the Power Button on the Display PCB.
4). To check the Power Button: Check from Black to Red you should read
a). IF you DO NOT have the voltage here you will need to disconnect power
for 30 seconds and then re-connect power to the machine (this will reset
the main PCB), then recheck for the 120 VAC.
b). IF you DO have the voltage; go to step 6.
c). IF you DO NOT have 120 VAC when you recheck, check the 120 VAC
supply voltage into the Line Filter from the Power Cord from BK to WH, and
out of the Line filter going to the Main PCB from BR to BL.
5). IF you DO have the voltage out of the Line filter from BR to BL, but not
at the Power Button from Black to Red you will need to check for 120 VAC
at the Main PCB on the other end of the wires from BR to BL. IF you DO
have the voltage; replace the Main PCB (after checking the Power Button
wire Connections (RD, YL, BK) at the 3 pin connector and at the Main PCB).
IF you DO NOT have the voltage the harness is open/replace harness.
6). (Before making this check disconnect power to the washer to reset or
this check may give you a false reading) Press the Power Button with your
meter connected between Black and Red. The 120 VAC reading should
drop to 0 VAC when the Power Button is pressed; IF 120VAC remained
steady on your meter; the Power Button has failed and you will need to
replace the Display PCB. IF you have the correct response of 120VAC
dropping to 0VAC, go to step 7.
7). Locate the (8-Pin Connector) which can be found in the center of the
machine right behind the console, it has 7 wires. The colors are: BK, BR, BL,
OR, RD, YL, and GR in the connector. Check the side of
the connector coming from the Main PCB for DCV from Ground (RD) to (YL)
= 5 VDC. Then Check from Ground (RD) to (OR) = 12 VDC.
8.IF you DO have the DC voltages replace the Display PCB after making
sure the connections are secure. IF you DO NOT have the DC voltages
replace the Main PCB.
NOTE: *(You will need needle probes to get into the back of the connector to make
good contact, otherwise it is very hard to press larger leads into the connector good
enough to make good contact for an accurate reading without possibly damaging the
connector. If you take any of the connectors apart and go in from the terminal end of
the connector you WILL DAMGAGE THE CONNECTOR AND MY HAVE TO REPLACE THE