I have a LG washing machine model WF-SP950G having no power problem, after check on the AC input power cable connected to control board found AC voltage between 2 pin connector, brown and blue wires is 120V and voltage between brown on previous 2 pin connector and adjacence 1 pin connector blue wire is 230V. Plug in back the connectors to control board, no LED lit at all and no sound at all after press the ON/OFF button many times. Check on all components in the board are new and no visual defect or burn marks. Any suggestion for further troubleshooting?

SOURCE: pulled the wires for the crts off. didn't label them correctly help

Yes the first one near the rear of the set goes to the blue crt which if you are looking in from rear will be on the far left and the middle will go to green in the middle and the 3rd or last will go to red on the right. A rule of thumb in this case is alway red on right and green is always middle crt.

SOURCE: Front Panel Connector: JFP1 hookup

You can go to the link below and see the directions for that. Turn to page 2-17

http://www.premioinc.com/pc/manuals/mb/m266/m266.pdf

SOURCE: Radio Aux feature and not plug connection

http://www.installer.com/cars/by_car.php?carid=6330

SOURCE: Does anyone know which connector to plug into on power supply

Double check all the connections from the AC line and from the power supply to the other circuit boards. The connectors you are mentioning are identical as per the picture below.
If you need a new power supply, you can find one from this link.

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SOURCE: oyxgon no.1 sensor replaced 2 time With code P0031

could be a fuse for the heater,check all fuses because some fuses feed other fuses and are not labeled as such

Testimonial: "I will check every fuse tomarrow, hope that works Cecil"