Brand: LG
Model Number: lfxs28968sw.aswna0
Main Symptom: No power to control panel, no lights inside, not cooling.
What happens & when:. We had a power surge recently and a test showed the fuse on the PCB was burned out. I replaced the PCB and now when I plug it in it seems to cycle (compressor comes on, evaporator fan comes on), but nothing else happens. Control panel is dead, no lights, no lights inside, water and ice dispensers are unresponsive. If I push the test button on the PCB it cycles through the various tests, but does not beep like I read it is supposed to do.
Error Code (if any): None
Parts or tests already tried: Replaced PCB with part # EBR74796444. Wondering if it is possible I got a bad PCB.
Photos / video link:
It is possible that there may have been a domino effect if the power surge was strong enough. There are voltage tests that can be done to identify if the main control is sending voltage out to the user interface on the dispenser. At the wire connection CON5 of the main control, there will be a red wire at pin 2 and a white wire with red stripe at pin 4 that can be tested for DC Voltage. If there is 12 Volts DC, the main control is sending the primary operation voltage to the user interface control. There is also a bright orange wire at pin 6 and a yellow wire with white stripe at pin 3 that should measure 5 Volts DC. If these check good, the next step would be accessing the user interface control at the dispenser and testing the same colored wires at the connection CON101. If voltage reaches that point, a domino effect did occur and the user interface has an issue as well. Here is a link to the user interface control just in case. EBR78631903 Display Power Control Board Assembly | Genuine Lg OEM In Stock
Thank you! I will check those things as well tomorrow and reply with the results.
I checked those outputs this morning. You said CON6 but I think you meant CON5, and you said yellow and white wire but I think you meant white and black since those 4 together go to the display PCB according to the wiring diagram on the back of my fridge. At any rate, I am not getting any voltage going from the main control board to the display control board on those wires (red, red/white or bright orange, white/black). Is it possible a capacitor was blown that is preventing the main board from getting the power it needs to send downstream? Like I said originally, the original board has a blown fuse and is completely dead. The replacement board has some signs of life, but is definitely not doing everything it should. Either we have a power delivery problem or the board was bad off the shelf.
Also, I should add, the LED light on the main control board does not illuminate. Everything I have read about running it through the self-test modes indicates the LED should blink. It responds when pushing the test button in the sense that various things respond, but the LED doesn’t so much as blink. While running it through those tests, the first one does result in about 4 volts going out of the main board to the control board at pins 2 and 4 (red, red/white wires), but that’s it.
Final update. I am an idiot. Didnt realize CON5 and CON6 wiring harness were interchangeable, even though one is white and one is red. My wife noticed that I had hooked them up backwards. Corrected that, plugged it in, and everything seems to be working.