LG 55LD520C Power Supply will not turn on.

[Ltank]

PS is EAY60869001. It will not turn on. It uses 3.5vdc not 5 for stby voltage. The Inv-on is low and does not change when trying to power it up so I used a 470 ohm resistor at the cable at the main board disconnected. Jumping the inv-on through the resistor to the 3.5 vdc stby and the power supply still doesn't turn on..Disconnected all cables except 120 vac input and it will not turn on. None of the voltages are shorted to gnd. The customer tried replacement main board. I have a service manual but it does not show how to test the SMPS. If I can't get the PS to turn on, I hate to buy another because I did not follow all the steps to correctly jumper it on. Will not come out of standby. Diodes Fets Caps checked fine. Fuses were good. No evidence of burnt or damaged parts.

[Ltank]

Re: LG 55LD520C Power Supply will not turn on.

Well I finally got it to turn on. Jumpered 3.5vdc through a 100 ohm resistor to Pwr term of P201 and then jumper from 3.5vdc to the Inv-on with a 100 ohm resistor. I got my 12 and 24 vdc. Backlights came on. It has to be the Main board. Cant find any used ones but new ones are available if the customer want the expense of a new board. Cable was disconnected from main board when jumpered.