Samsung LN46C600F3FXZA No backlight

[budm]

Re: Samsung LN46C600F3FXZA No backlight

FB is the LAMPs current sensing Feed Back signals used for maintaining the constant lamp brightness, it is in mVAC (Vdrops across very low Ohms resistors).
LD is the lamp detection signal to indicate that if the lamps are good when fired up and Lamps stay on.
>11VDC = Good, <9VDC = Bad.

[Vegasdog11]

Re: Samsung LN46C600F3FXZA No backlight

If this helps anyone, I had all of the same issues with my Samsung LN46C630K1F, I could not get the backlights to power on no matter what I replaced, Anyway , I stumbled upon this thread and saw Zalinar's post about replacing the C1818 film capacitor and figured why not give it a shot. Well, IT WORKED!!! I ordered "47uF 450V U47 Epcos film capacitor for Samsung Power Supply BN44-00341B" off of eBay and this is what fixed my backlights. I really hope this is successful for someone else also because it took me 2 months to figure out why these backlights would not fire up. Good Luck to all.

[dick_barton]

Re: Samsung LN46C600F3FXZA No backlight

Thanks for the useful tip.

[budm]

Re: Samsung LN46C600F3FXZA No backlight

If this helps anyone, I had all of the same issues with my Samsung LN46C630K1F, I could not get the backlights to power on no matter what I replaced, Anyway , I stumbled upon this thread and saw Zalinar's post about replacing the C1818 film capacitor and figured why not give it a shot. Well, IT WORKED!!! I ordered "47uF 450V U47 Epcos film capacitor for Samsung Power Supply BN44-00341B" off of eBay and this is what fixed my backlights. I really hope this is successful for someone else also because it took me 2 months to figure out why these backlights would not fire up. Good Luck to all.

Do you mean 0.47uF? That cap failed a lot in the Samsung P.S. board.

[Vegasdog11]

Re: Samsung LN46C600F3FXZA No backlight

Do you mean 0.47uF? That cap failed a lot in the Samsung P.S. board.

Yes .47 uf is correct.

[sockmonster2]

Re: Samsung LN46C600F3FXZA No backlight

Thank all of you very much for your postings! I too was given a free no picture Samsung (no backlight).. replaced C1818 and now works great!! Oh how I love the internet!

[edbiggins]

Re: Samsung LN46C600F3FXZA No backlight

Hi guys, I just wanted to post a big THANK YOU for budm, Vegasdogg11, sockmonster2, Zalinar, and so on for taking the time to post about Capacitor C1818 on the Samsung LN46C600F3FXZA power supply board. I had a little trouble finding the cap because it's hard to see the silk screen identifier, but having read your posts I stayed on it and located it. I don't know how I missed it the first time, but the cap was definitely blown and looked like it melted onto the adjacent heat sink. After desoldering it and testing it I was able to confirm it was bad.

THANK YOU ALL!

[PfhorSlayer]

Re: Samsung LN46C600F3FXZA No backlight

I too would like to thank everyone in this thread for the C1818 tip! I am having the same backlight problem, and totally missed that the capacitor was slightly bulging when I did a once-over of the power supply board, as the bulging side happened to be the one shoved right up next to the adjacent heatsink. I've ordered a replacement cap, and hopefully everything will work once I've swapped out the broken one!

[C152Heavy]

Re: Samsung LN46C600F3FXZA No backlight

Hi guys, I just wanted to post a big THANK YOU for budm, Vegasdogg11, sockmonster2, Zalinar, and so on for taking the time to post about Capacitor C1818 on the Samsung LN46C600F3FXZA power supply board. SNIP!

THANK YOU ALL!

Just a quick note here to bring this thread back to the top after being dormant for the last 3 years, please add me to the list of appreciative people who have used the information here to repair their Samsung LN46 family of TVs, in my case it's an LN46C630K1F with the same issue.

THANK YOU!

For posterity the backlight would sometimes not start on startup until it didn't start at all. Of course it always did it to the S.O. so I didn't have first hand info to work with.

In my case C1818 showed no physical signs of failure but fixed the problem.

Now, for a follow-on question if I may. I also procured electrolytic caps to replace those on the board but to date haven't, any advice on this other than the usual of replace them because they are electrolytics? Is this a known failure mode for this board? The existing caps are SAMWHA.

Thanks!

D