Hey guys. So no backlight at all. not even a flash. I'm getting 330 volts at the connector for the back light. Would mean I have a problem with the strips themselves correct?
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Re: hisense 55K20DG no backlight
Pictures of the boards with the back of the tv off may help you more with fixing your fault
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Re: hisense 55K20DG no backlight
Here is picture of backlight strips. Burned out but whyAttached FilesComment
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Re: hisense 55K20DG no backlight
They drive those LED to the max and with poor heat management.
Once you get it fixed you should then turn down the backlights level to as low as you can.
Yours is not as bad as the one in LG TV's.
https://www.badcaps.net/forum/showth...ht=LG+47LN5790Never 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: hisense 55K20DG no backlight
I had a Samsung 40" about a month ago that the led's got so hot it and shorted it caught the white diffuser sheet on fireDid I leave the soldering iron on?Comment
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Re: hisense 55K20DG no backlight
wow thats nutz! Thanks for the pictures. Time to order some parts.Comment
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I bought this p2210f dell monitor to fix. Schematic is the same as p2210.
Behaviour is that monitors comes on but then backlight switches off almost instantly. If I look with flashlight I can still find the "No signal message". So definitely a backlight issue. Trying to advance the issue I proved that the protection circuit is switching off the backlight by shorting out C3 and resistor to disable the INL chip then re enable by removing the short.
This is where it gets interesting. When I disassembled the monitor to solder leads on c3 capacitor I noticed the backlight flickered... -
Hello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
I2C_BKLT_SCL and I2C_BKLT_SDA both measure... -
My tv still has backlight when turn on, 12v on tcon board but no picture and 6 flashing red light at power button. I already disconnected each ribbon cable in turn but the screen only had backlight and nothing changed. -
Ok.. this is the story:
Have an old Samsung LED 3D TV (UE55F6475). First it started to lose light on the lower 40% of the screen now and then. Like for 10-60 mins and then it would work again. Then a bit later it just got stuck in that position. The lower 40% of the screen is dark, and it gets progressively darker the lower u go so it's obviously that LED strips where not working. I also looked for similar errors online and saw an exact copy and on that one it was faulty LED strips.
This is kinda how it looked, just that mine were at the bottom of the screen:
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Hi folks.. Would appreciate your help.
Hisense TV that doesn't turn on (no pic, no backlight)
Flashlight tests shows activity on the screen (Hisense ROKU) then off then again.
On the connector from PS to main, I see Vstandby (2.5 V), VAMP (16.9V) and 12V (11.86 V)
As the TV cycles, VAMP goes from 16.9 to 17.6V then back to 16.9V
Any thoughts? never seen a standby voltage as low as 2.5V. Not sure if backlight is bad, but that doesn't explain the reboot cycle - right?...
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