Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
New T-CON board came in... TV is working perfectly again.
Thanks for all the help Budm!
Cryptic78
Andy
Last Activity: 06-20-2019, 11:45 AM
Joined: 01-07-2018
Location: Milwaukee, WI
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Still no VIN with TCON to LCD ribbon cables disconnected. Reads ~15mv still....Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
I'm OK with that. $63 +$10 shipping on ebay for a NEW board. I appreciate the help and learning experience....Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Pin 4 basically says at 12.38v while pin 1 reads 12.55v
I repeated the test a few times... On pin 4 I can see a few blips where voltage goes down, but not long enough for it to stabilize on a DMM, but it ultimately stabilizes at 12.38v
The drains are reading just millivolts...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
ic101 = 4435b mosfet...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Yes on how I measured BD103. Just noting the slight difference in voltage. I don't know if that is relevant or not.
What's our next steps? Is that MOSFET not passing the voltage as it should?...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
TV on:
BD103 (top or bottom) to VIN = 12.40v
BD103 (top or bottom) to chassis ground = 12.55v
VIN to chassis ground = 18.5mv and OL testing continuity.
IC101 = 4435B MOSFET
I hope that helps....Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
OK getting some different results now.
VIN to BD103 (like you highlighted before) now reads 12.5v. I also notice a fast pulse sound coming from somewhere when I test these two points.
VIN to Panel VCC and the top of C11 has continuity and reads .3 ohms and stray voltage around 0-13mv.
VIN to the bottom of C11 reads OL
Hopefully we are getting somewhere
...
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Nothing. OL...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
I disconnected each ribbon cable from the TCON to the LCD (one at a time) and I do not see any difference. Just a backlight....Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Found a few more spots with continuity to VIN, but still no 6-12v source.
How else do I approach this?...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
This is the backside of the board. Highlighted in yellow is where the VIN pad should be... so I am a little confused on where to proceed from here.
I guess I am a little ignorant here. What am I looking for, for a power source?
I'll try to probe around some more...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Found continuity to two locations, they all read the same voltage
Resistance between GND and VIN = 131k ohms (took awhile for it to settle)...Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
VIN = 34mv
AVDD = 13mv
Please advise and thank you....Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
History: Been mine since Black Friday of 2009 when it was first released. we have a spritz bottle we use to clean TV screens. I doubt I ever let cleaner run down the screen.
Not finding VIN or AVDD..... I'll try again tomorrow. I gotta turn in for the night
Thanks,
Andy...Last edited by Cryptic78; 01-08-2018, 10:48 PM.Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
F1 and F2 both have continuity. I checked voltage as well. 12.2v on both.
I checked all 3 fuses on the power board. All good....Last edited by Cryptic78; 01-08-2018, 08:27 PM.Leave a comment:
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Re: 2009 Samsumg UN55b8000xfza - backlight - no picture
Pics of powerboard and main...Leave a comment:
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2009 Samsumg UN55b8000xfza - backlight - no picture
I have a samsung un55b8000 LEDtv (model #un55b8000xfza) that when I turn on I can see the backlight turn on but no picture. I hear the power on and off melody though speakers. The blue light flashes when turned on.
It used to take a few attempts, turning on and off a few times or let it warm up then off/on again to get the video to come through. Now it just never does. I suspected caps. Nothing is visually bad on the power board.
I've only probed around doing in-circuit testing on the power board.
I've got two [URL="https://www.infineon.com/dgdl/Infineon-SPP_I_A20N60C3-DS-v03_01-en.pdf?fileId=db3a304318f3fe290119090054e32a20"]20N60C3[/URL]... -
Re: New Members - please post your introductions here
Hello,
Just joined. Troubleshooting a 2009 Samsung UN55b8000xfza.Leave a comment:
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