I have Samsung UN55ES6150 TS01 tv that has a backlight that flashes/flickers/strobes. I have disconnected the cable between main board and power supply and the backlight stops flashing/flickering/strobing. I checked the voltage on power supply (BN44-00503a) CNL802 pin 4 (R-) and pin 6 (l+) and both are 141v each. It is also steady. If I reattach the cable between main board and power supply and plug in the tv it is steady and good at 141v for about 5-7 seconds and then the screen starts flickering/flashing/strobing and the voltage starts bouncing between 138-142. What is correct voltages on CNL802? Please help troubleshoot. BTW this pattern happens regardless of the input and the image is fine...it just strobes/flashes/flickers.
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Re: samsung flashing/flickering/strobing
Turning the backlight down to the lowest setting does not have any effect.
By disconnecting the cable between the mainboard and the power supply the problem goes away. Does disconnecting the cable stop the led strips from powering?
Any other thoughts I can test to confirm?
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Re: samsung flashing/flickering/strobing
The main board sends a backlight on (BL-ON) signal to the power supply to turn on the backlights and a PWM signal to dim them. By disconnecting the cable, there is a pull up on the power supply to keep the backlights on. Flickering is a sign of LED failure. Very tricky on large edge lit models to replace the strips.
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Re: samsung flashing/flickering/strobing
" I have disconnected the cable between main board and power supply and the backlight stops flashing/flickering/strobing." When you perform this self test, the LEDs are driven at max. So the backlights stay on solid without flickering as long as the power is applied to the power supply board? If the LED are going bad then I would expect it to be flickering in self test mode.
Can we see the pictures of the whole backside of the TV showing all the boards?
May be the Dim control signal is varying and causes flickering.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: samsung flashing/flickering/strobing
I wanted to provide more feedback for the flickering behavior. After power on AND NO INPUT source connect the following happens:
1. SamsungSmartTV logo flashes on screen
2. Tv presents message that there is 'weak or no signal'. No flickering at this time.
3. After 10 seconds the screen momentarily goes black (like it's sent a command to redraw the screen) and then is starts flickering.
4. If an input source is connected then step 3 does not happen for up to a few minutes before the screen starts flickering. The amount of time it takes varies between 1-4 minutes.
These behaviors regarding the different responses due to the input source is consistent. I've tried all HDMI inputs on the back with the same result.
Hope this helps diagnose.
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Re: samsung flashing/flickering/strobing
But do the backlights flicker if you do not have main board connected (power supply self test mode) and run it for 5 minutes or more? You indicated it does not flicker in post #1.Last edited by budm; 05-12-2020, 06:36 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: samsung flashing/flickering/strobing
Hook everything back up and test pin 2 of connector CNM803 PWM_DIM, power tv on, what is the voltage and is it steady?Last edited by nomoresonys; 05-13-2020, 08:16 AM.
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Re: samsung flashing/flickering/strobing
What I did:
1. Reattach mainboard to power board
2. Power on unit
3. Measure pin 2 @ 1.99v (steady) UNTIL screen starts flickering (about 10 seconds). When screen is flickering the voltage fluctuates between 1.79 and 2.2v and it never settles down while the screen is flickering.
1. Power off unit
2. Detach mainboard from power board
3. Turn unit on
4. Measure pin 2 @ 3.13 (steady) never fluctuatesLast edited by zuehls; 05-13-2020, 09:11 AM.
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Re: samsung flashing/flickering/strobing
I've disabled all the eco settings I could find including the following but it has no effect.
energy saving
eco sensor
no signal power off
auto power off
One thing I've noticed is that when I adjust the backlight from 0-20 it does not make any noticeable difference on the screen. Does that point to anything?
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Re: samsung flashing/flickering/strobing
Does the set have Motion Lighting and if so is it set to ON. If so does turning it OFF stop the flickering
When on, the TV automatically adjusts the brightness of the screen in response to the brightness of the room. In bright light, the screen brightens. In dim light, the screen dimsWilling to help but I'm no expert.
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Re: samsung flashing/flickering/strobing
Originally posted by zuehls View PostI've disabled all the eco settings I could find including the following but it has no effect.
energy saving
eco sensor
no signal power off
auto power off
One thing I've noticed is that when I adjust the backlight from 0-20 it does not make any noticeable difference on the screen. Does that point to anything?
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Re: samsung flashing/flickering/strobing
After power on AND NO INPUT source connect the following happens:
1. SamsungSmartTV logo flashes on screen
2. Tv presents message that there is 'weak or no signal'. No flickering at this time.
3. After 10 seconds the screen momentarily goes black (like it's sent a command to redraw the screen) and then is starts flickering.
Can anyone shed light on what could be happening in this sequence to cause the flicker? Is there anything technically happening 10 seconds after the TV message 'weak or no signal' due to no input source being attached that would cause a shift in the stable backlight and causing it to flicker? Why wouldn't it start flickering from go?
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