since initial posting, I opened up the TV and had a good look at the power supply board (BN44-00150A), where I found three capacitors that were bulging and oozing brown crud. (Marked on circuit board as CM812, CM813, and CS804). They look just like the failed capacitors I've seen on computer motherboards from the early 90's when there was apparently a big problem with some kind of off-spec electrolyte. Anyway, I have located what appear to be matching capacitors on DigiKey (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=565-1504-ND) so am going to attempt to repair the board. Will post back results.
Does anyone have an opinion about whether I should replace the other similar capacitors on the board? There are two more of the same type that are not oozing, but I'm thinking if there is a whole batch of bad capacitors, then I may as well replace all five while I'm in there with the soldering iron...
my LN-T5265F stopped displaying video yesterday. It is out of warranty, so I am hoping to diagnose the problem myself before having an on-site service visit. I created a short demo video on Youtube here:
Here is the sequence of events when I turn on the set:
-press power button, hear click, see blinking red LED
-after a couple of seconds, I see a faint glow from the set, i.e. it changes from black to a dark gray, so I think the backlight is on.
-at the same time the glow starts I hear a faint buzzing/crackling sound -- it sounds like very quiet electrical arcing (but I don't smell anything)
-a second or so after the buzzing starts, the video comes on very briefly -- less than a second, and then goes black. At that point, the buzzing stops, but the audio from the programming continues.
Have tried a total set reset with no change (not sure I did it correctly -- pressed remote control "exit" for 12 seconds, then down arrow, then enter ???) Have also tried unplugging for several hours with no change.
Is this enough info to make a definitive diagnosis of the problem? Maybe the power supply board? Or do I need to gather more info.