Less than a year out of warranty, samsung UE49MU6105K craps out, they've got this designed obsolescence down to an exact science of self destruct when out of warranty...
Screen started to show horizontal lines and ghosted image at the bottom, then turned off by itself. Did software update, to no avail of the line problem, and got a boot loop after some minutes of watching TV. This boot loop will turn on the backlights for some seconds the sound comes on, the image will turn dark very fast and then it reboots again. Pressing power button will not put it on standby. Disconnecting power to main board allowed backlight to stay on. Left it disconnected for a while and then tried powering up. Still got the horizontal lines, but less than initially, a pronounced line plus some fainter ones. At this point I noticed the whole screen had a staircase degradé/dithering, when watching closely, looks like a bad inkjet print where you can see the dithering and spacing/lines between the printed rows. On the right side of the screen an inch/couple of cm above the bottom a lighter spot that is hot to the touch (no other spot on the screen is this hot) is where the problem seemed to originate (I expected a burnt COF or something) but I disassembled and peeked under this side and there's no tabs or other components on the right side of the screen, only at the bottom that I could see. Is a short inside the panel, apart from breaking it, even possible?
Left unplugged overnight as the mainboard was making some electrical noise (not sure if it was always there with the back side fitted). When turning back on the next morning got the boot loop again. Tried the "quick fix" taped pins 4 to about 14 on the first flat cable this seemed to had fixed the "boot loop" problem. Taping some of the last pins on the second cable eliminated the black line, still some almost unnoticeable lines (and the whole screen staircase dithering) remained.
This wouldn't be too bad, but next morning just a boot loop again... so the taping didn't really "fix it"
Nothing looks obviously burnt or bulged. The power board voltages look ok, 12v , 3.3v ... tried disconnecting the PWM BLU pin but basically still a longer cycle boot loop (someone used this to fix another samy to have backlight always on)
The lower board with the integrated T-con and tabs/COFs to the screen visually looks good, nothing obviously burnt. All the SMD resistors show open circuit or very low ohm, like 20. Many cases on youtube where bad resistors have closed circuit and replacing them plus removing some overcurrent SMD fixes it.
The voltage though I got 7.5v and 15v on some, when this board is marked VSS - 7.6 and VOFFE_-11v but found another marking with AVDD 17v... so not sure if this is a problem.
sticker on mainboard:
UE49MU6100WXXN
BN94-1243B
MOEDL (sic) : KANT_M_BUILT_IN
CODE: BN41-02568B
MODEL: BN41-02568
SIZE: 193X241 1.6t
Date:2017.03.20
sticker near power board:
BN96 - 44229A NO REV
BN96 - 44229A SHC "B"
49" MU 6100 22.2.2018
sticker near LED connector:
CY-GM049HGLV1H
BN95-04219A
SK09BN9504243AS001K310544
Made in Slovakia 49A6AU0VM
markings on tabs/COF circuit board:
dynamic KM1-V0
E255400 94V-0
16Y VU49SR4LV0.1
stickers on tabs/COF circuit board:
8GHL3J0E0A 1752
LSF490FN02-L15
BN96-39044A
T36123D7LIRZ6
22205C
VNB U60F
markings on powerboard:
L55S6R_MHS BN44-00807F
sticker: CN07BN4400807FAM5RJCI5399 R.B
All help is much appreciated.
Screen started to show horizontal lines and ghosted image at the bottom, then turned off by itself. Did software update, to no avail of the line problem, and got a boot loop after some minutes of watching TV. This boot loop will turn on the backlights for some seconds the sound comes on, the image will turn dark very fast and then it reboots again. Pressing power button will not put it on standby. Disconnecting power to main board allowed backlight to stay on. Left it disconnected for a while and then tried powering up. Still got the horizontal lines, but less than initially, a pronounced line plus some fainter ones. At this point I noticed the whole screen had a staircase degradé/dithering, when watching closely, looks like a bad inkjet print where you can see the dithering and spacing/lines between the printed rows. On the right side of the screen an inch/couple of cm above the bottom a lighter spot that is hot to the touch (no other spot on the screen is this hot) is where the problem seemed to originate (I expected a burnt COF or something) but I disassembled and peeked under this side and there's no tabs or other components on the right side of the screen, only at the bottom that I could see. Is a short inside the panel, apart from breaking it, even possible?
Left unplugged overnight as the mainboard was making some electrical noise (not sure if it was always there with the back side fitted). When turning back on the next morning got the boot loop again. Tried the "quick fix" taped pins 4 to about 14 on the first flat cable this seemed to had fixed the "boot loop" problem. Taping some of the last pins on the second cable eliminated the black line, still some almost unnoticeable lines (and the whole screen staircase dithering) remained.
This wouldn't be too bad, but next morning just a boot loop again... so the taping didn't really "fix it"
Nothing looks obviously burnt or bulged. The power board voltages look ok, 12v , 3.3v ... tried disconnecting the PWM BLU pin but basically still a longer cycle boot loop (someone used this to fix another samy to have backlight always on)
The lower board with the integrated T-con and tabs/COFs to the screen visually looks good, nothing obviously burnt. All the SMD resistors show open circuit or very low ohm, like 20. Many cases on youtube where bad resistors have closed circuit and replacing them plus removing some overcurrent SMD fixes it.
The voltage though I got 7.5v and 15v on some, when this board is marked VSS - 7.6 and VOFFE_-11v but found another marking with AVDD 17v... so not sure if this is a problem.
sticker on mainboard:
UE49MU6100WXXN
BN94-1243B
MOEDL (sic) : KANT_M_BUILT_IN
CODE: BN41-02568B
MODEL: BN41-02568
SIZE: 193X241 1.6t
Date:2017.03.20
sticker near power board:
BN96 - 44229A NO REV
BN96 - 44229A SHC "B"
49" MU 6100 22.2.2018
sticker near LED connector:
CY-GM049HGLV1H
BN95-04219A
SK09BN9504243AS001K310544
Made in Slovakia 49A6AU0VM
markings on tabs/COF circuit board:
dynamic KM1-V0
E255400 94V-0
16Y VU49SR4LV0.1
stickers on tabs/COF circuit board:
8GHL3J0E0A 1752
LSF490FN02-L15
BN96-39044A
T36123D7LIRZ6
22205C
VNB U60F
markings on powerboard:
L55S6R_MHS BN44-00807F
sticker: CN07BN4400807FAM5RJCI5399 R.B
All help is much appreciated.
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