Nordmende LCD-TV - defective SMPS (JSK4180-024/A/B) primary capacitor blowing up

[freccia]

Hi all,
I have a fault in the power supply of a Normende lcd tv. At switch on the led turns from red to blue. The lcd switches on and the display shows no signal on screen. After around 20seconds, the capacitor in the primary, 120 microfarads 450volts becomes very hot and steam comes out of it. I changed this capacitor 2 times, but the same happens every time. On standby(red led), smoke is not seen from this capacitor.
Any ideas about how to tackle this problem? Any help would be appreciated. Thanks

[Armadillo]

Your power factor controller circuit is defective.
You can temporary remove D2 from the circuit, put in a new capacitor 150uF/450V 105C and use your TV.
But of course proper way is to repair the PFC.

[Armadillo]

Your power factor controller circuit is defective.
You can temporary remove D2 from the circuit, put in a new capacitor 150uF/450V 105C and use your TV.
But of course proper way is to repair the PFC.

After you have confirmed defective PFC and if you want to repair your TV fully [must have PFC, can't live without it];

Measure one by one each of the resistors R25, R37, R38, R39 are correct values, if so then change the PFC controller L6562.

EDIT: I LOG IN AGAIN TO REMIND YOU TO DISCHARGE THE CAPACITOR BEFORE WORKING ON IT.

[freccia]

Thanks a lot for the info. Will check the resistors and maybe the ic as well.

Sorry for the trouble, my fault, assumed that the circuit diagram was the one I was looking for but I got this circuit diagram from this web site and it says Nordmende N3202lb, but it does not match my power supply, it has different component numbers. on the power supply I have STA208tv rev B02. Does anyone have this circuit diagram please.  Or at least the chassis number for this model please? Thanks

[Armadillo]

Thanks a lot for the info. Will check the resistors and maybe the ic as well.

Sorry for the trouble, my fault, assumed that the circuit diagram was the one I was looking for but I got this circuit diagram from this web site and it says Nordmende N3202lb, but it does not match my power supply, it has different component numbers. on the power supply I have STA208tv rev B02. Does anyone have this circuit diagram please.  Or at least the chassis number for this model please? Thanks

Hard to find for this schematic. The board is just single sided. I think you would have to trace to the PFC controller without the schematic.   

[freccia]

I think I found that diode you were talking about. I think it is the one attached to the heat sink, connected to the fet. Will try to remove that and see what happens.