Samsung PN51F5300AF will not power on

[dhack61]

OK Need some help. Plasma's just drive me nuts.
Got TV son said made a loud pop and went off with no power. Opened it up and found that the fuse was blown and part of the copper trace on the back of the board had burnt. Replaced PS with Ebay unit, now getting 5.3v standby and nothing on the PS ON. The main board LED flashes 5 times then nothing. If I disconnect the cable from the CN801 on the PS I do get 4.3v at the PS ON pin. Next was to replace the main board which I did but I get the exact same outcome. At the at the IR connection test points on the main board I get
Func_led 1.7v
Key 2 3.2V
Key1 3.2V drops to zero when on button pressed
MSDA 3.2v
A 3.3v 3.2v
IR 3.2v

I get no VS ON when power button pressed and have no clicking relays when set is plugged in.
Also nothing at the VA & VS test points

Needing to know where to go next. Back to PS, Main problems or XY Drive.I can provide more data from Main board test points if needed.

Thanks
Dhack

[martino]

Re: Samsung PN51F5300AF will not power on

Did you try and force on the power supply by itself and see if all voltages are there?

[dhack61]

Re: Samsung PN51F5300AF will not power on

No I have not. How is that done exactly?

[ReeceyBurger123]

Re: Samsung PN51F5300AF will not power on

I had this on a PS50C450 where the Psu blew up and took out the firmware on the mainboard which is stored on its epprom so it no longer gives the Pson and Vson signals. I ended up replacing the whole mainboard and Psu and the Tv worked. Look up for a video on youtube called "worst Psu repair ever" by MrReeceyBurger123 which is me and thats the Tv im on about.