Samsung LE32B651 - sound and no video

[flyone]

Hello

When I start my Samsung TV all is ok but time to time in a ranomly basis backlight switch off, sound is ok and I can see the picture on the LCD panel with the help of a strong external light source. When this problem occurs i have to switch off / on the TV to get the picture again.
Since 2 or 3 days the problem is getting worse et I cannot use the TV anymore.

Here are some pic of the board inside.

what can i di to fix this ?

thanks for your help !

[tom66]

Re: Samsung LE32B651 - sound and no video

Which country are you located in? 115V or 230V mains?

The transistor QP801 has got very hot. This could cause its solder joints to crack, which would possibly cause lack of backlight. I advise you resolder all of the transistor solder joints and see if the issue persists. Cold solder joints are a very common issue with Samsung TVs.

[tom66]

Re: Samsung LE32B651 - sound and no video

It's your lucky day, I have schematics for BN44-00261A and BN44-00261B.
My SM site hosts these and I still have FTP access to it. Hopefully main site will be up by tomorrow...

[flyone]

Re: Samsung LE32B651 - sound and no video

Hello

Thanks for such a quick answer !

I'm in France where the main voltage is 230 V

I'm going to resolder these transistor right now, i'll keep you in touch about the result.

[tom66]

Re: Samsung LE32B651 - sound and no video

Just remember to do them all, it'll only take a few minutes, and this will ensure that you won't encounter future issues. If you can, use leaded solder.

Where I said QP801 I meant to say QP802S.

[flyone]

Re: Samsung LE32B651 - sound and no video

Works done...

I have good trust in this soldering job because the tv is in much more better condition than this morning. I hope it was just that. I'll come back in a few days to make a report.

Thanks again for the advice

[tom66]

Re: Samsung LE32B651 - sound and no video

I hope it resolves your issue.