Occasional flicker on start up with backlight set to max of 10. If you turn backlight down it gets worse. Mostly more apparent on TV setting rather than external inputs. Anybody know of a fix or might it be failing CCFLs?
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Re: Samsung LE40B550 flickering backlight
Forgot to mention in my last post. Its a PSU with built in inverter BN44-00264C rev1.3. There are no swollen caps and everything tests ok. -
Re: Samsung LE40B550 flickering backlight
How about some photo's to start you off. Clear sharp pictures of your boards and back of the set would be useful.Willing to help but I'm no expert.Comment
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Re: Samsung LE40B550 flickering backlight
Do the backlights still flicker with the main board unplugged?Comment
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Re: Samsung LE40B550 flickering backlight
Is the DCV between the two legs of the main cap steady and close to 380~400VDC?
It may be due to UVLO is detecting border line PFC Boosted Voltage, or the detection circuit itself (Resistor network, ICP802, PCI801S), similar problem with the other SAMSUNG that people cut the jumper off the UVLO Opto circuit instead of fixing the PFC Voltage problem due to drifted resistors value in the PFC feedback circuit.
I suspect the resistors string in the RP802/06/09/13 string for PFC Voltage feedback, or the RP837/803/810/807/823 string for the UVLO detection circuit.Last edited by budm; 05-27-2016, 03:36 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=24809Comment
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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=24809Comment
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Re: Samsung LE40B550 flickering backlight
Thanks for your response. Shortly after posting this fault found out it was caused by the PFC micro (FAN 7530). Once this was replaced together with 4 smd resistors (RP802,RP806,RP809,RP813) the fault cleared. Appreciate all of your replies.Last edited by satinser; 05-27-2016, 07:36 PM.Comment
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Re: Samsung LE40B550 flickering backlight
Thanks for the follow-up.
So was the PFC Voltage was <360VDC?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=24809Comment
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Re: Samsung LE40B550 flickering backlight
Yes it was between 350 - 358vdc.Comment
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Hello All,
My Samsung LE52B620 started to have backlight flickering about a year ago, it would only last for about 10 mins and then the backlight would stay on.
about a month ago the backlight flickering is constant and does not stop.
I think it's a problem with the power supply board (BN44-00267b) or maybe the backlight is dying?
I checked and all the caps look to be fine.
I do not believe it is a problem with the mainboard, since I unplugged it from the power supply and the backlight came out but still flickers.
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This specification for the Samsung Galaxy Book 2 Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the Galaxy Book 2 boardview and Galaxy Book 2 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...09-07-2024, 05:50 AM
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Hi everyone!
Hope you're all having a great day, and thank you very much for stopping by and taking the time to read this post to help me with my parents' Samsung TV.
My issue: No backlight.
Model: QE82Q70RAT
Type No: QE82Q70RAT
The TV was already serviced by Samsung once under warranty for the exact same issue, but six months after the fix, the backlight went out again. Now, Samsung is asking for nearly the same price as a brand new TV to fix this with the same 6-month guarantee.
So hopefully, I can fix this cheaper.
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TV was fixed just after removing Samsung's rear snap cover.
This curved TV's construction is rather interesting. When the snapped on back is removed, rest of the TV will relax the curvature. Top of LCD panel is loose as it wants to straighten out against the slightly curved bezel. Snapped back provide most of the curvature shape. So just simple disassembly of rear cover will allow the rest of the TV frame to relax its curvature. Thats probably what fixed it but no idea which connection. 4x LEDs are edge lit.
Maybe PSU->backlight connector didn't have a good contact?...07-23-2025, 12:34 AM -
- Prior owner tried a replacement main board. No difference.
- Samsung 2x red blinking standby LED = panel fault
- Jumpered FB_TRDY_1 (pin 1 CN1300 left. main tcon->left side buffer boards) and FB_TRDY_3 (pin 95 CN1301 right. main tcon->right side buffer boards) This allows testing individual T-Con (on main board) connection to panel on this Samsung. Found fault on left side (viewing from rear of TV)
- Each side has 2 buffer boards, disconnected left side flex between 2 buffer boards. Fault is on the left most board.
- Tape masking eventually isolated to CN1300 pin 15 (CKV4_GOA) Display
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