Samsung LN46C610N1F LCD TV no backlight

[tech2014]

I can see video if I shine a flashlight on the screen, but I get no backlight. It doesnt even come on for a second. The fast track manual said to remove connector off main board and the BL should turn on as soon as power is applied. I still get nothing. Here are my voltages off connector CNi802 from the backlight inverter board to the power supply, I get the following voltages:

CN802-

Pin 1- VCC 12v=12v
Pin 2-FB=0V
Pin 3-FB=0V
Pin 4 and 5 are GND
Pin 6 and 7 LD=8.84V

For PW dimming out on CN802 of p/s, I get 2V and H_out=1.66V

I tested the PFC voltages and I get 388V on filter cap so PFC is good. I am suspecting the 2 large inverter transformers on the PS or the inverter board is bad.

[budm]

Re: Samsung LN46C610N1F LCD TV no backlight

What is the board P/N BN44-XXXXXX? Samsung BN44-00341B? I suspect bad coupling cap, white rectangular cap CI818 0.47uF 450V POLYPROPYLENE in the middle of the board next to the heatsink for the MOSFETs that drive the inverter transformer. Look real close to see if is has bulge on the body.
BTW, the fuse on the middle of the board is OK?

[tech2014]

Re: Samsung LN46C610N1F LCD TV no backlight

Bn44-00341b and fuse is good. I removed the capacitor and tried measuring the capacitance and get no reading, just OL.

[tech2014]

Re: Samsung LN46C610N1F LCD TV no backlight

Does anyone know where I can get this capacitor?

[budm]

Re: Samsung LN46C610N1F LCD TV no backlight

Showing no capacitance at all?
It will be PANASONIC POLYPROPYLENE type from DIGIKEY with 630V rating instead of the 450V rating.

[tech2014]

Re: Samsung LN46C610N1F LCD TV no backlight

Showing no capacitance at all?
It will be PANASONIC POLYPROPYLENE type from DIGIKEY with 630V rating instead of the 450V rating.

I can't find this part on digikey. Anyone know? thanks

[vinceroger69]

Re: Samsung LN46C610N1F LCD TV no backlight

http://ca.mouser.com/Passive-Compone...PYLENE&FS=True

[R_J]

Re: Samsung LN46C610N1F LCD TV no backlight

http://www.digikey.ca/product-search...=PCF1574-ND%20

[tedjar]

Re: Samsung LN46C610N1F LCD TV no backlight

Just want to report that this this thread saved another TV...

I had a Samsung LN46C630K1FXZA with the same issue. Power on, works normally if you shine a light at the screen, no backlight at all. All electrolytics looked ok. Power supply is the same BN44-00341B. The poly cap was bad, completely open. It even had the little bulge on the side of it. Replaced it with DigiKey P/N: PCF1574-ND - Panasonic / ECW-FA2J474J CAP FILM 0.47UF 5% 630VDC RADIAL and the TV is back to normal.

[budm]

Re: Samsung LN46C610N1F LCD TV no backlight

Thanks for the report, I wish the OP has done the same.