Samsung LE40R73 backlight issue.

[Dang]

This is mostly OK, in that the back light works and can stay on for a good few hours but on some occasions the back light will turn off, I understand this is a common fault but not too sure on where to start looking, as I say it is fine mostly but needs to be 100% so if you can help in diagnosing as to what this is, it would be greatly received, thanks.

[tom66]

Re: Samsung LE40R73 backlight issue.

Start by checking the BL ON/OFF signal going to the power board from the main board.

[Dang]

Re: Samsung LE40R73 backlight issue.

Thanks Tom66, it seems it might be this:

http://www.youtube.com/watch?v=XdsDxKkcesg, that's the exact same power supply I have, I shall give it a closer inspection later.

[Dang]

Re: Samsung LE40R73 backlight issue.

Upon looking I had the exact same issue, so a quick dab of solder and all seems fine now.

[selldoor]

Re: Samsung LE40R73 backlight issue.

That is a great fix!! Can you post the Power supply board number - may help others in future.

[Dang]

Re: Samsung LE40R73 backlight issue.

That is a great fix!! Can you post the Power supply board number - may help others in future.

I've put the Tv back together now but I believe it to be this one: BN44-00134A, a quick look on Ebay will confirm.

[selldoor]

Re: Samsung LE40R73 backlight issue.

Yes, that looks likely, thanks.
I also notice there are a lot of repair kits available for it - suggesting the caps
are not too good - did you replace yours?

[Dang]

Re: Samsung LE40R73 backlight issue.

The caps looked perfectly fine with the Tv starting up after 4 flashes, all perfectly usual from my experience so no need to change.

[johnboy1313]

Re: Samsung LE40R73 backlight issue.

Just picked up a LNS4051DX-XAA with the same BN44-00134A power supply. The caps had all been replaced in the last year but it wasn't working again. I found the same bad solder joint on the backside. A touch up on that cold joint and the set is working like new again.

[dick_barton]

Re: Samsung LE40R73 backlight issue.

An old post but just goes to show how helpful it is when you follow up and inform us of your repair.

Thanks to this thread I've just repaired an identical fault with the backlights on an LE40R73BD. The transformer solder joints looked fine but decided to add fresh solder and the set has now been running for the last 4hrs, not 15-20 minutes.

[ReeceyBurger123]

Re: Samsung LE40R73 backlight issue.

Had same issue, transformer broke through the soldered rivet. Resoldering fixed the issue.

[FIXITNOW]

Re: Samsung LE40R73 backlight issue.

Just had one come my way was recap a year or so ago found this post and tip for joints in transformer TI801 cheers folks