Samsung PS51D6900DS (S50FH-YB09) power problem

[tech2014]

With everything connected the tv powers up and no sound from the power supply(relay). Removed the p/s from set and shorted PS_ON and used 3.3k resistor to VS_ON and got all my voltages(VA,VS) and 5.3v, 15v. The LED doesn't come on at all, but there is 5v standby and LED on front of tv flashes red.

I removed the YSUS and XSUS boards from the set and connected them to the p/s on my bench and p/s clicks on and I get my VS,VA VE,VSC.

When I tried isolating the faulty board in the set, by removing connectors one at a time, I still get nothing(no relay clicks) and no LED on logic board.

Could this point to a faulty logic or main board?

[steviewonder]

Re: Samsung PS51D6900DS (S50FH-YB09) power problem

the solenoid needs to click,to provide the switched 5v to the logic board,in every Samsung plasma I have so far come across..the green lamp should flash even with nothing else connected to the pcb,bar 5v supply.

[tech2014]

Re: Samsung PS51D6900DS (S50FH-YB09) power problem

I found that with everything in the tv connected, when I remove the ribbon cable going from the YSUS to the logic board, and also remove the cable going from the YSUS to XSUS, the power comes on and stays on, and the LED flashes on the logic board. As soon as I reconnect the ribbon cable or XSUS board , the power only comes on for a couple seconds then drops. the LED on the logic boards is on solid.

I found that the 5.3v line on the power supply only measures only 90ohms.