Good day folks. Thought I'd report my findings on another one of these Samsung tellies and how I managed to fix it, so let me tell you a story first
The reason I'm doing this is because it seems to be a fairly common occurrence, having encountered it myself and read about it a lot now, so I thought I'd add another one to that pile to perhaps same someone out there some time and effort. The first time I ran into this, I got stumped a lot before finally figuring it out, with a little help from our wonderful chaps here of course. I thought the issue might've been a one-off sort-of deal and didn't make a big deal out of it back then, but then I saw it happening again....and again...then read a post here of someone else who was struggling with it and managed to fix it "together" the same way. Here's the original post
The backlight wasn't coming on....yeey. Now it may not sound like anything special and your first thought will be a bad backlight LED, mine was too of course, but they all checked out fine - exactly the same scenario as everybody else having this issue. To make a long story short, the problem is the power supply itself: it's a BN44-00493B in this case, but I imagine it can happen to other similar supplies as well, despite not having seen it myself, at least not yet.
Even though you may be getting something out of the LED connector, like 160v, the LEDs still refuse to turn on, not even a flash or anything, and that's because of a faulty cap, CM867. Now here's the interesting bit which is bound to screw a lot of people over, me included: no visible signs of failure on this cap, so without an ESR meter you might look at it and think, nope, this one looks fine - leave it alone and move on...that was until, on a whim, I decided to pull it out and replace it anyway, since I had just about exhausted every other possibility at this point, including replacing the SLC1012C IC, checking and rechecking all resistors, even SMD ones and every last voltage on there. Turns out it WAS faulty: it had leaked through one of its legs, so that was the issue: I replaced it and I was all good do go.
Now the same thing happened just as I'm writing this, so this being like the 4th time seeing this, I thought I just HAVE to write about it
My buddy had already opened up the TV and checked the LEDs for me, but of course he got stumped the same way I did and had no idea what to check next, being at wits' end. After having a look myself, not trying to be cocky or anything, I went straight to that cap, pulled it out and lo and behold: failed leg once again, except unlike the last time where the leg was fine but the electrolyte spewed out and wasn't particularly obvious unless you got in really close with a magnifier, this leg had completely broken off, showing signs of corrosion. Replacing it instantly fixed the issue, so this goes to show that capacitors can fail even without showing it...which is nothing new, but larger ones like these usually tend to bulge, so you might disregard it initially thinking it's fine, when in reality it's leaked through the BOTTOM instead. In this case at least it's the exact same capacitor with the exact same issue, so it's particularly interesting and strange at the same time. Cheers guys

The backlight wasn't coming on....yeey. Now it may not sound like anything special and your first thought will be a bad backlight LED, mine was too of course, but they all checked out fine - exactly the same scenario as everybody else having this issue. To make a long story short, the problem is the power supply itself: it's a BN44-00493B in this case, but I imagine it can happen to other similar supplies as well, despite not having seen it myself, at least not yet.
Even though you may be getting something out of the LED connector, like 160v, the LEDs still refuse to turn on, not even a flash or anything, and that's because of a faulty cap, CM867. Now here's the interesting bit which is bound to screw a lot of people over, me included: no visible signs of failure on this cap, so without an ESR meter you might look at it and think, nope, this one looks fine - leave it alone and move on...that was until, on a whim, I decided to pull it out and replace it anyway, since I had just about exhausted every other possibility at this point, including replacing the SLC1012C IC, checking and rechecking all resistors, even SMD ones and every last voltage on there. Turns out it WAS faulty: it had leaked through one of its legs, so that was the issue: I replaced it and I was all good do go.
Now the same thing happened just as I'm writing this, so this being like the 4th time seeing this, I thought I just HAVE to write about it


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