Samsung LCD issue

[eclef]

Hello I was wondering if anyone can help with a problem. It should be known that I am not very technically minded, I have soldered/de-soldered tact switches in some audio equipment before, out of necessity. I was hoping my TV would be a capacitor issue because I feel comfortable replacing those. Samsung wont help for free.

Basically it's a 19" lcd model number LS19CFEKF/EN. It won't turn on properly - pressing the on button on the tv or remote, will either do nothing at all, or it will go funny and the screen/backlight will flash, or the blue LED lights will go on and off, but it wont actually turn on.

The only way to make the tv come on, is by switching it OFF at the mains, leaving it 5-10 mins, switching it back on, waiting 5 minutes, then turning the tv on by the remote.

I got into the back of the TV to look at the capacitors, and none of them seem bulged or burst. They are all flat and normal.

Is there anything else obvious that the problem could be? I don't have any equipment to test voltages etc etc, in honesty all of that goes over my head a bit. But if I can be pointed in the direction of a simple component i need to replace for example, that would be really useful (I dont think I'll end up paying through the nose to fix it otherwise).

Any information would be really helpful. Thanks in advance

[selldoor]

Re: Samsung LCD issue

It is virtually impossible to make suggestions on what to replace if you are unable to test it first.
I would guess ( have you not read any posts on here) without pictures that there are very few caps on the power supply. They will probably be samwha or samyoung in which case replace them all EXCEPT the BIG cap unless it looks bulged or leaky with low esr panasonic fm fr or fc caps. The small ones are important, one, possible 50v 47uf is a startup cap.

[eclef]

Re: Samsung LCD issue

Thanks for your response. They are indeed samwha and samyoung. There are a group of medium/normal size caps, as well as a small and an even smaller cap. The small and smaller ones are 35v/47uf and 50v/10uf respectively. I'm not sure if this helps but I have taken a few pictures as well which I have attached. Does this sound like it's probably a startup-cap issue, and would it be a reasonable idea to replace that cap alone and see if it works?

Which of those two smaller ones sounds like the startup cap? The 35/47 one is isolated and the rest are in a bunch together, if that helps.

Thanks

[selldoor]

Re: Samsung LCD issue

It has to be on the primary side - cant see much from the pics not clear enough. Primary or HOT side is marked on the board it is inside the black line.

[eclef]

Re: Samsung LCD issue

Great I can see that, okay so the most of them are on cold side and the solitary one is in the hot side. So that is the start up capacitor. I've never used the camera on this phone before and I'm shocked how bad the quality is - sorry about that. I've done the best I can taking a picture of that cap, although that's still probably useless to you. You can see though that it's not obviously bulging or anything..

Would it be a decent idea changing that cap first and seeing how it goes?

Thanks again I appreciate your time

[selldoor]

Re: Samsung LCD issue

As I said I would change them all bearing in mind the postage (unless like me you can just pop around the corner and buy decent caps one at a time.) If that one doesnt do it and you have to change the rest then you will probably have paid more in postage than you did for caps. But yes - given your description of the problem you could try just that one. If that fixes it then you should still change the rest because those caps are thought of as being poor so as they deteriorate from just being bad to even worse and that can put pressure on other more expensive and more difficult to replace components

[eclef]

Re: Samsung LCD issue

Thanks very much for your help. I'll give that a go tomorrow and hopefully I wont be back with any more questions! I'll probably take your advice and replace the lot, might as well.

Cheers!

[roberto100it]

Re: Samsung LCD issue

Worked for me! Replaced the three caps above (photo taken before soldering the last on right) and voilat! Fixed with a 1 euro cost of caps!



Thanks guys!