LG 26LE3300 blinking power LED fix (CL-81 Chassis)
Good day folks. I thought I'd offer my small bit of contribution to our beloved community by presenting to you how I managed to fix a small LG TV the other day which drove me to the very brink of insanity, since I couldn't find a similar solution anywhere else and it had more than one issue, so hopefully this will help someone out there who's desperately looking for a fix to one of these as I did 
Of course, you mileage may vary.
The TV would only turn on very sporadically (if at all). Sometimes you'd get sound but no backlight and other times it wouldn't come on at all, or at least not after cycling the power a lot, so this was officially a bad power supply. Opening up the cabinet confirmed this, as I immediately noticed 4 out of the 5 Samson (if memory serves) caps were dead and buried (bulging and leaking). They're the ones in that cluster in one of the pictures, though I took it towards the end of the repair job, only after I figured this might be worth sharing, otherwise it would've just been a standard, boring cap replacement job.
Obviously the replacement ones aren't of spectacular quality either. Just some Samwha which everybody here says they're terrible and shouldn't be used, but at least they're new, so please don't comment on that So there's two 680uF ones and 3 1000uF caps, so I replaced those and put the TV back together, fully convinced that was the only issue and there's now way it wouldn't work now.
To my dismay, now the thing wouldn't turn on AT ALL: the green LED at the front would blink continuously in roughly 1 second intervals, but it wasn't the sort of blink that would signal an error code, instead more like something was trying to turn on but failed due to a short or overload.....great.....open the thing up again and try to figure out what happened. The PSU was definitely working: I manually switched it on (PS_ON to 5v) and got the correct voltages at its output, both 15v and 5v, even under load from a car headlight (definitely pushed it beyond what it's meant to handle), so that wasn't it. I obviously turned my attention to the main board now, as much as I feared I'd have to do this, since I'm not a fan of SMD stuff, but it's necessary. You can just about make out the model in one of the pictures: it's a "Blue Bird" 2(17a) 68709M0005K 060525 (I now realise how much of a dipsh!t I was not talking a clear picture of the damn model number, probably the most important thing 
). Couldn't find any shorts, which would most likely point towards a dead CPU, which would've been slightly infuriating considering it sort-of worked sometimes...couldn't just die like that.
The next thing I wanted to try was heating up the main board, so I blasted it with some hot air evenly all around, until it was just about too hot to touch and then plugged it in: now the LED remained lit permanently, so there was a bad cap somewhere. I let the board cool down and began heating less and less surface area each time, trying out the board after each pass, rinse-wash-repeat, until I narrowed it down to the area on the left side of the CPU, under the power connector. There's 3 poly caps there, though it took me a while to figure out exactly which one was the culprit because at this point they were so close together that trying to heat them up individually also unavoidably warmed up the neighboring ones, so it was slightly trickier to identify, but I eventually got it. Long story short, it's the one immediately above the mounting hole, C410, 22uF 16v (it already had flux on it when I took the picture). Replaced it and now the green LED stayed on each time, job done .........or was it ?
Put the TV back together once more, again positive it HAD to come on this time. The TV did turn on from the first attempt, but there was still no backlight. I could see the picture on screen was steady so it passed the "flashlight test".....well damn....open the thing up AGAIN, ripping the hair out of my skull and wondering what the hell broke down now :|
I thought it's a bad lamp doing this, the TV being fairly old now. It uses an unusual 3-lamp setup, so I didn't have a separate display with that many lamps to test it with, so it turned into a guessing game at this point. I decided to investigate the other possible end of the issue, which is the HV transformers. Taking some resistance readings, I didn't have any large offsets between any of the 6 transformers which would indicate one is faulty, so I turned my attention back to the lamps. The controller is a BIT3105 so I tried for like an hour to disable its open-lamp protection to see if the lamps came on at all, which supposedly involves isolating pin 4 and letting it float, but got no results with this at all - the lamps simply refused to come on. I was just about ready to throw in the towel, despite the fairly heavy-work and components I had put into it by this point, that was until I noticed a lonely capacitor right above the BIT IC (where the arrow is).....surely didn't LOOK faulty, but as a final try I decided what the hey, let's change it...tried it out and holy sh!t it works.....go figure...green light, backlight....all fine and dandy...
So there you have it, three consecutive and apparently unrelated problems within the same TV, at the core of all of which however lie bad caps. Areas affected: power supply, CCFL driver, main board. The last one I find particularly interesting, because I couldn't find this fix anywhere else. I'm not too proud of my workmanship though, because instead of closing the TV up every time, I should've properly tested it and not count my chickens before they hatch Lesson learned. Cheers guys. Hopefully you've enjoyed reading this and possibly having a laugh at my mishaps as much as I enjoyed writing and messing with this thing
Of course, you mileage may vary.The TV would only turn on very sporadically (if at all). Sometimes you'd get sound but no backlight and other times it wouldn't come on at all, or at least not after cycling the power a lot, so this was officially a bad power supply. Opening up the cabinet confirmed this, as I immediately noticed 4 out of the 5 Samson (if memory serves) caps were dead and buried (bulging and leaking). They're the ones in that cluster in one of the pictures, though I took it towards the end of the repair job, only after I figured this might be worth sharing, otherwise it would've just been a standard, boring cap replacement job.
Obviously the replacement ones aren't of spectacular quality either. Just some Samwha which everybody here says they're terrible and shouldn't be used, but at least they're new, so please don't comment on that
So there's two 680uF ones and 3 1000uF caps, so I replaced those and put the TV back together, fully convinced that was the only issue and there's now way it wouldn't work now.To my dismay, now the thing wouldn't turn on AT ALL: the green LED at the front would blink continuously in roughly 1 second intervals, but it wasn't the sort of blink that would signal an error code, instead more like something was trying to turn on but failed due to a short or overload.....great.....open the thing up again and try to figure out what happened. The PSU was definitely working: I manually switched it on (PS_ON to 5v) and got the correct voltages at its output, both 15v and 5v, even under load from a car headlight (definitely pushed it beyond what it's meant to handle
), so that wasn't it. I obviously turned my attention to the main board now, as much as I feared I'd have to do this, since I'm not a fan of SMD stuff, but it's necessary. You can just about make out the model in one of the pictures: it's a "Blue Bird" 2(17a) 68709M0005K 060525 (I now realise how much of a dipsh!t I was not talking a clear picture of the damn model number, probably the most important thing ). Couldn't find any shorts, which would most likely point towards a dead CPU, which would've been slightly infuriating considering it sort-of worked sometimes...couldn't just die like that. The next thing I wanted to try was heating up the main board, so I blasted it with some hot air evenly all around, until it was just about too hot to touch and then plugged it in: now the LED remained lit permanently, so there was a bad cap somewhere. I let the board cool down and began heating less and less surface area each time, trying out the board after each pass, rinse-wash-repeat, until I narrowed it down to the area on the left side of the CPU, under the power connector. There's 3 poly caps there, though it took me a while to figure out exactly which one was the culprit because at this point they were so close together that trying to heat them up individually also unavoidably warmed up the neighboring ones, so it was slightly trickier to identify, but I eventually got it. Long story short, it's the one immediately above the mounting hole, C410, 22uF 16v (it already had flux on it when I took the picture
). Replaced it and now the green LED stayed on each time, job done .........or was it ?Put the TV back together once more, again positive it HAD to come on this time. The TV did turn on from the first attempt, but there was still no backlight. I could see the picture on screen was steady so it passed the "flashlight test".....well damn....open the thing up AGAIN, ripping the hair out of my skull and wondering what the hell broke down now :|
I thought it's a bad lamp doing this, the TV being fairly old now. It uses an unusual 3-lamp setup, so I didn't have a separate display with that many lamps to test it with, so it turned into a guessing game at this point. I decided to investigate the other possible end of the issue, which is the HV transformers. Taking some resistance readings, I didn't have any large offsets between any of the 6 transformers which would indicate one is faulty, so I turned my attention back to the lamps. The controller is a BIT3105 so I tried for like an hour to disable its open-lamp protection to see if the lamps came on at all, which supposedly involves isolating pin 4 and letting it float, but got no results with this at all - the lamps simply refused to come on. I was just about ready to throw in the towel, despite the fairly heavy-work and components I had put into it by this point, that was until I noticed a lonely capacitor right above the BIT IC (where the arrow is).....surely didn't LOOK faulty, but as a final try I decided what the hey, let's change it...tried it out and holy sh!t it works.....go figure...green light, backlight....all fine and dandy...
So there you have it, three consecutive and apparently unrelated problems within the same TV, at the core of all of which however lie bad caps. Areas affected: power supply, CCFL driver, main board. The last one I find particularly interesting, because I couldn't find this fix anywhere else. I'm not too proud of my workmanship though, because instead of closing the TV up every time, I should've properly tested it and not count my chickens before they hatch
Lesson learned. Cheers guys. Hopefully you've enjoyed reading this and possibly having a laugh at my mishaps as much as I enjoyed writing and messing with this thing
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