I have a a very strange problem. My TV is a Samsung LE46A558P3F.
It is to do with the backlight settings. If I go into 'menu', and change 'backlight' to anything above 5, the screen cuts out - as in, completely black.
The tv is still on and audio is still fine. I have memorised the remote sequence to turn the backlight back down to 5. Doing so doesn't make the display work again straight away - but by powering off and on, it's working again (with backlight set to 5).
If I pull up the menu and set backlight to 4,3,2,1,0 the screen gets progressively darker, as you'd expect. Going 0,1,2,3,4,5 gets lighter again, as you'd expect. But as soon as you hit 6, the screen gets brighter for just a second then goes black. The only way to get picture again is as described above - doing it 'blind', use the remote to set the backlight to 5 or less, power off and on, tv is fine again. In fact, if you set it to 'dynamic' (which sets the backlight at 10) and power cycle the tv, again you get you get the nice bright picture you'd expect for just a second before going black again.
This is all regardless of input, by the way. All inputs - DTV, Ext1&2, HDMI1&2 behave the same way - will only display anything if backlight is set to 5 or less.
I am an electronics engineer to trade and have no issues with taking my TV apart (it's way out of warranty). I would like some advice, however, if this problem is known to you and if you can advise what the most likely part is that needs to be repaired/changed - the PSU, the mainboard, or the inverter/slave?
Hello Bob , my name is Jack
Perhaps I can help you with this problem but I saw that you asked this question yesterday (sept/9) and would like to know if you still need help with it ?
Yes please, I haven't had an answer yet. I'm still using the tv (albeit with a dimmer screen than I'd like) but if you have seen this problem before and can point me in the right direction I can get a spare board off ebay and give it a try. The good thing about this issue I suppose, is that 90% of these type of tv's that are dead, have had their screens broken - so there's lots of people who strip them down and sell off the boards as spares.
Or maybe I have one of the PSU's that has the dodgy capacitors on it that I've read about some models of Samsung suffering, which would be an even easier fix... (I haven't had the back off it yet to see if any caps are burst)
That's a great tip, thanks. I had been looking at ebay and found psu's, mainboards and inverter master&slaves all running at about £35-ish but if these guys can do a complete set at 65 is well worth it. Seems I might get another year or three out of the tv... I also got my hands on the service/repair manual for it from a Russian site for €4.95
Thanks again, I'll get started on looking into buying those spares from the site you mentioned.