Full model: 50PK950-UA.AUSALJR
Symptom details: When TV is off, it will power on all by itself within 10 min. to 3 hours, but almost always within 30 mins. (more than 30 min. is very rare).
Note: TV owner later reported TV also turns itself off (rarely), but I've never experienced this (although I usually am leaving it off to troubleshoot the self power-up issue.
Current state and conclusions: Problem is not on main board or front control panel/sub board (control panel plugs into sub board), but unplugging sub board stops TV from turning itself on, although this doesn't prove it's the cause. (see history below)
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Detailed history of what I've tried and how I arrived at my conclusions:
1. Suspecting the main board (because the TV owner hadn't told me the TV turned OFF by itself, too) I sent the main board into an eBay repair service because they said they could fix the self power-up issue, as well as address the common issues with these main boards that I requested they do for preventative maintenance.
I got the main board back and the TV was still turning itself on. The eBay seller said he didn't experience it turning on by itself before or after testing the board, but I think they didn't even test it long enough and there was a language barrier; I don't know that they even understood the symptom or request. I think they just reflowed the BGA and maybe reflashed the eeprom.
2. I had a friend with the same model test this main board in his TV to see if it was causing the self power-on symptom and after 2 days, it never turned itself on. I reinstalled the main board into my TV and confirmed the symptom was still present. I talked to the TV owner and asked if the TV ever turned itself off, because I would have suspected the front touch pad (capacitance controls on this model), but they had originally only reported self power-on. They said it rarely DID turn itself off, so my attention was drawn to the front control panel/touch pad.
3. I first disconnected the cable from the main board going to the front touch pad SUB board (EBR65007705) where the capacitance pads or front control buttons plug into a small circuit board called the SUB board by LG, where the IR sensor also is located. This stopped the TV from turning itself on with repeated and lengthy test periods. I then replugged that cable in and tried JUST UNPLUGGING the ribbon cable that goes underneath the board into the bezel of the TV where the capacitance pad is. Testing showed that the TV would starting turning itself on again in this state. I then repeated the test where I unplugged the SUB board from the main board to confirm THAT is what stops the TV from turning on. Confirmed. Problem found, right? WRONG! Haha.
4. I ordered a SUB board from eBay, because a new one would take 4 weeks from LG. I put the board in when it arrived, but the TV still turned itself on. I repeated earlier tests and it acted the same way. Could have gotten a bad board from eBay, but doubted it. I borrowed the SUB board from my friend's TV (who didn't want to let me borrow it because he said I MUST have gotten a board and thought my tests PROVE that SUB board is the cause, but I wanted to be sure before ordering the new board from LG). Anyway, the borrowed board ALSO didn't stop the TV from turning on by itself and that board was known to be good because it's been in my friend's TV for days without causing self power-on.
Conclusion as to why unplugging the SUB board stops the TV from turning on by itself: the TV can't turn on in that way with that circuit disconnected, so it can't prove anything.
5. I pulled the power supply and resoldered poor connections that I found, but that didn't help.
6. I posted on badcapsforums because I know my pals here will help me solve this insane problem! LOL
Symptom details: When TV is off, it will power on all by itself within 10 min. to 3 hours, but almost always within 30 mins. (more than 30 min. is very rare).
Note: TV owner later reported TV also turns itself off (rarely), but I've never experienced this (although I usually am leaving it off to troubleshoot the self power-up issue.
Current state and conclusions: Problem is not on main board or front control panel/sub board (control panel plugs into sub board), but unplugging sub board stops TV from turning itself on, although this doesn't prove it's the cause. (see history below)
-------------------------------------------------------
Detailed history of what I've tried and how I arrived at my conclusions:
1. Suspecting the main board (because the TV owner hadn't told me the TV turned OFF by itself, too) I sent the main board into an eBay repair service because they said they could fix the self power-up issue, as well as address the common issues with these main boards that I requested they do for preventative maintenance.
I got the main board back and the TV was still turning itself on. The eBay seller said he didn't experience it turning on by itself before or after testing the board, but I think they didn't even test it long enough and there was a language barrier; I don't know that they even understood the symptom or request. I think they just reflowed the BGA and maybe reflashed the eeprom.
2. I had a friend with the same model test this main board in his TV to see if it was causing the self power-on symptom and after 2 days, it never turned itself on. I reinstalled the main board into my TV and confirmed the symptom was still present. I talked to the TV owner and asked if the TV ever turned itself off, because I would have suspected the front touch pad (capacitance controls on this model), but they had originally only reported self power-on. They said it rarely DID turn itself off, so my attention was drawn to the front control panel/touch pad.
3. I first disconnected the cable from the main board going to the front touch pad SUB board (EBR65007705) where the capacitance pads or front control buttons plug into a small circuit board called the SUB board by LG, where the IR sensor also is located. This stopped the TV from turning itself on with repeated and lengthy test periods. I then replugged that cable in and tried JUST UNPLUGGING the ribbon cable that goes underneath the board into the bezel of the TV where the capacitance pad is. Testing showed that the TV would starting turning itself on again in this state. I then repeated the test where I unplugged the SUB board from the main board to confirm THAT is what stops the TV from turning on. Confirmed. Problem found, right? WRONG! Haha.
4. I ordered a SUB board from eBay, because a new one would take 4 weeks from LG. I put the board in when it arrived, but the TV still turned itself on. I repeated earlier tests and it acted the same way. Could have gotten a bad board from eBay, but doubted it. I borrowed the SUB board from my friend's TV (who didn't want to let me borrow it because he said I MUST have gotten a board and thought my tests PROVE that SUB board is the cause, but I wanted to be sure before ordering the new board from LG). Anyway, the borrowed board ALSO didn't stop the TV from turning on by itself and that board was known to be good because it's been in my friend's TV for days without causing self power-on.
Conclusion as to why unplugging the SUB board stops the TV from turning on by itself: the TV can't turn on in that way with that circuit disconnected, so it can't prove anything.
5. I pulled the power supply and resoldered poor connections that I found, but that didn't help.
6. I posted on badcapsforums because I know my pals here will help me solve this insane problem! LOL
I appreciate you coming into the thread to help and offer suggestions!
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