Originally Posted by dukewald
My set has stopped powering on. The red light remains solid. I have pulled the back off to inspect the capacitors on the power supply. I do not see and bulging/failure. Has anyone run into this?
Hi Dukewald, I know it is much later than you originally posted asking about the issue with your tv not powering up, but I did not see any further replies than the basic check the power and remote answer. To belatedly reply to your question or for anyone else who may have B750 that exhibits the issues you mention I hope my experience can be helpful.
I actually just had this problem occur about two weeks ago. I'll give you a short rundown so you can maybe compare to your own experiences.
I happened to be sitting down and introducing my five year son to the glory and the folly of the Star Wars universe. Although not my favorite, I threw in Phantom Menace thinking that for a five year old this would be a decent place to start and not as dark as A New Hope or Empire. My son was a bit tense when the Trade Federation decided to end negotiations with the Supreme Chancellor's representative, but was glad to see them escape to the surface of Naboo. Everything (with the tv) was fine until the invasion of Naboo. At the exact moment, and I kid you not, THE EXACT MOMENT that Jar Jar barrels into Qui-Gon an enormous bolt of electricity (not unlock the Emperor's dark energy that he tortures Luke with in Ep. 6) stretched out of the top of the tv to the ceiling and a very short time later we heard an equally loud popping sound. The screen went to black and all we had was the solid red power light.
I went through the normal routine of checking the surge protector, swapping surge protectors, plugging in and unplugging the tv, etc. without any luck of a change of state for the tv. This is when I really began to freak out and panic. My only focal point being my renewed hatred of Jar Jar for not only ruining the best space epic of all times, but also for causing the downfall of my B750 Series 52 inch. Here is clear evidence that Jar Jar's clumsiness extends well beyond the vivid mind of Mr. Lucas.
Later, much later, after many exhausting hours that must have been at least as long as Solo's run to Kessel, I found an exchange between a soul experiencing similar issues with his tv and a helpful tech.http://www.justanswer.com/tv-repair/5yexd-samsung-ln52b750-tv-2-1-2-yrs-old-just.html
Once I was finished reading and re-reading the exchange I decided to unmount my tv, remove the back, and compare my tv to the symptoms noted. Since my symptoms were not exactly like the other fellows, I was more interested in the steps needed to troubleshoot what might be the issue. What seems to be common (several articles, plus DIY videos on youtube) is that the power supply board capacitors eventually wear out and quit. One of the symptoms is that the power light flashes and the back lighting for the tv does not power on.
Just for orientation purposes when you take the back off the tv there are two boards approximately 12 inches by 12 inches. One on the right (the power supply board) and one on the left (the main board). I looked over the power supply board and I did not see any capacitors that looked to be bloated, leaking, etc.so I was not sure that this was my issue. I was able to test this by unplugging the white ribbon cable that connects the power supply to the main board ONLY on the main board side. I left the cable connected on the power supply in order to test jumpering pins as needed to try and power on the board. It turns out that it was not necessary for me to jumper anything as just unplugging the cable was enough that when I plugged the tv back into the wall outlet I heard one relay click and the backlighting came on. I figured that meant the power supply board was good to go. If it were a power supply capacitor issue I did not think the relay would be able to switch and stay on. I'm not an electrician, electrical engineer, or electrical hobbyist, so I definitely could be wrong in my thinking.
Next I moved on to the mainboard as being the potential issue. I unscrewed the four screws that held the board on and picked it up from the frame. As soon as I picked it up I could see char/carbon on the metal frame of the tv and the underneath side of the circuit board had a charred area about the size of a nickel directly on the other side of the ethernet jack. I now suspect that clumsy b*st*rd struck by going through the network cable I had attached to the tv.
Now the hard part. If you are able to diagnose this as the issue good luck trying to find a place online that sells them (and actually has them in stock). These boards are more elusive than the location of the rebel base. It wasn't as if I were looking for a hold full of Kaiburr crystals.
I ended up ordering one from this place in California: http://tvserviceparts.com/LN52B750U1FXZA.html
. There website stated the part was in stock, but after I ordered it turns out the part actually was not in stock. The shipment was delayed but eventually did ship a week later than planned. Honestly though, I don't think it's worth getting the Hutts involved. One week delay isn't really worthy of a lifetime in carbonite or a date with a Rancor. None the less, it was a bit frustrating to wait for an in-stock part to be in-stock enough to ship.
I actually just received the part today and installed it. It was ridiculously simple that I can't imagine how much I would have paid someone to do this for me. There wasn't a better sound that I heard today than the factory setting chime informing that all of my custom settings no longer existed but that I would have a picture to look forward to the rest of my night. The settings deal is actually why I happened to be visiting this thread that I haven't looked at in many months. I used the custom settings that a few folks here recommend and I happened to run across your posting.
Now with all that written, I don't know if my issue is your issue, but I think/hope you'll find the first link provided useful in trying to troubleshoot your symptoms. If it is the same or if you can narrow it down to a different component then the second link would be a place I would recommend. Other than the small delay, the part shipped on time on the revised date, it was well packaged, and it worked.
FYI, just in case you would like to know, the part I ended up replacing was the BN94-02585B
. There seem to be other interchangeable parts recommended, but I don't know if they will end up working so you may want to ask whomever you order from if they can confirm the alternative part works the same as the original.
Take care and good luck,