Samsung Power Board Help!!!

[bwilliamson04]

Hi and this is my first post. My father-in-law has a 46" Samsung LCD TV (LN46C600F3F) that turns on with no picture but has sound. I think I have identified the culprit as a bad capacitor (silver metal spewed out the side), but I can't find a replacement. The picture below is a similar one I cropped on a picture from the internet. It says 2W 474K on top and then SIC 460S on bottom. Anyone know where I can buy a replacement instead of buying a whole new board (Hansol BN44-00341B)? Any help or direction would be greatly appreciated as money is tight right now! Thanks.

[tom66]

Re: Samsung Power Board Help!!!

Can you highlight the defect - cap looks ok to me?

Standard questions... did set fail suddenly or get worse over time, any pinkish tint from screen when working (indicative of failing tubes), and any other issues to report?

[tom66]

Re: Samsung Power Board Help!!!

BTW, schematic, in case it helps... http://www.tgohome.com/ServiceManual...g_BN44-00341B_[SCH].pdf

[bwilliamson04]

Re: Samsung Power Board Help!!!

Thanks guys. I dont have a picture of it, that one I cropped off the internet. Its the white box capacitor that has solder looking material coming out the side of it. I tested for continuity and there was none. Thank you for the Schematic. From what I can see I need a 47nF 450V capacitor?

From what he told me was that the picture was lost on one channel and then he switched to another and it was there, but then it went again and hasn't had a picture since. The sound plays fine. I get no voltage at all from where it goes to the backlight board so I'm 99% sure its not a backlight issue.

[bwilliamson04]

Re: Samsung Power Board Help!!!

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[budm]

Re: Samsung Power Board Help!!!

That white stuff is the glue for keeping the cap in place, good cap should read open circuit, need to read its capacitance, it is Metalized Polyester Film type cap, I do not think it is bad from the look of it.
I think we will need more pictures and some voltage readings of the board first.

[bwilliamson04]

Re: Samsung Power Board Help!!!

bdum, That's not the actual part (grabbed pic off internet). The actual piece is leaking the lead or whatever metal was used.

[budm]

Re: Samsung Power Board Help!!!

Well. then we need the pictures of the part in question, pictures will be the only thing we have to troubleshoot the problem since we do not have the board in front of us to look at.
" I tested for continuity and there was none. Thank you for the Schematic. From what I can see I need a 47nF 450V capacitor"
Capacitor should have no continuity reading, if it does, then it is bad.

[bwilliamson04]

Re: Samsung Power Board Help!!!

oh, ok. I'm a newbie ;-). I'm 2.5 hours away from the problem board so I can't take a picture but I can tell you it has metal solder looking material coming out the side so its definitely shot. I think I'm narrowing my parts search down to a 470nf (.47uF) 450V Film Capcitor. Now is that 450V AC or DC? I know its on AC but I thought I remember reading on the board some DC ratings. This is what I have narrowed down to:
http://www.digikey.com/product-searc...k=470nf%20450V

Also, Here's a shot of the same board, the capacitor in question would be the white film capacitor in the middle; again this was taken off the internet as I dont have access to the board right now. thanks for everything so far guys.

[budm]

Re: Samsung Power Board Help!!!

0.47uf 450VDC Polyester Film type.

[bwilliamson04]

Re: Samsung Power Board Help!!!

Thanks and I'm assuming I should try for +/- 5%? Is there any better than another?

http://www.digikey.com/product-detai...1253-ND/592830

[budm]

Re: Samsung Power Board Help!!!

5% should be good. The one you have on the link is fine.

[bwilliamson04]

Re: Samsung Power Board Help!!!

Thanks, I really appreciate all your help! I hope this works.

[triplefour]

Re: Samsung Power Board Help!!!

So did it work? i just got one of these TV's and it blows the primary fuse. considering replacing this part as i see it on ebay so maybe this is a common problem for this tv?


kinda strange though the picture of the whole board u have here does match mine, but the first picture posted of just the cap in question, doesnt look like it comes from that same board....cant find it any where.

none of mine are leaking anything :/

[tom66]

Re: Samsung Power Board Help!!!

Won't normally resolve a fuse blowing; you'll have shorted FETs or a bridge rectifier somewhere, I'll bet.

[triplefour]

Re: Samsung Power Board Help!!!

yeah guess id better get to probing... can i test fets in circuit? is there a guide on here how to test fets and bridge rectifiers and stuff?

[tom66]

Re: Samsung Power Board Help!!!

Yes you can. All you want to do for now is check across all pin combinations for obvious shorts (<20 ohms); if you find a short, remove the device and check out of circuit to be sure.

When you find shorted FETs it is almost always necessary to replace the driver chip that controls them, usually a small surface mount part.