Re: Phillips TV no backlight
Did you test it out of circuit?
Did you test it out of circuit?
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Re: Phillips TV no backlight
Yes i did.Comment
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Re: Phillips TV no backlight
That's a head scratcher, if you could get the working board again, you could test them both with your meter, seems like the faulty component should test off, unless you have a bad solder joint or something like that?Comment
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Re: Phillips TV no backlight
Wonder if C9105 could be the problem?Comment
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Re: Phillips TV no backlight
It is a 1Mohm resistor.
The schematic says both R9102, 9103 are 5% so should read a minimum of 0.095M and a maximum 1.05M. Measure without your fingers touching the probes or end of the resistor since that will affect the reading.Willing to help but I'm no expert.Comment
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Re: Phillips TV no backlight
Ok, its silver not gold, so 1.05ohm.Last edited by nomoresonys; 05-07-2018, 05:30 AM.Comment
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Re: Phillips TV no backlight
According to post 17 it's a little over the 5 %, 943m, I would switch it out, just to eliminate it from suspect, might explain why your meter probe kicks the lights on.Last edited by nomoresonys; 05-07-2018, 05:46 AM.Comment
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Re: Phillips TV no backlight
Anyone pls help?Comment
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Re: Phillips TV no backlight
Pictures are out of focus, can't read the numbers.Comment
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Re: Phillips TV no backlight
Did you measure the resistors you use to replace the existing ones and (with your meter) and were they within the resistance range indicated in an earlier post bearing in mind their % tolerance.Last edited by dick_barton; 05-07-2018, 10:12 AM.Willing to help but I'm no expert.Comment
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Re: Phillips TV no backlight
Never mind, the schematic does not match your board.Last edited by budm; 05-07-2018, 10:29 AM.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: Phillips TV no backlight
Is C9105 (22nF) capacitor case cracked on top?Attached FilesLast edited by dick_barton; 05-07-2018, 10:43 AM.Willing to help but I'm no expert.Comment
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Re: Phillips TV no backlight
BTW, what is the P/N of that IC9101? LCS700LG?
https://www.badcaps.net/forum/attach...7&d=1525502099
I am trying to read the P/N of that bracode sticker.
Is it PLTVEY741XA, FSP600403 3073086?
C9102 (100N 50V) is OK? You can try tagging on another cap in parallel to see if the power supply will stay on.Last edited by budm; 05-07-2018, 12:05 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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Re: Phillips TV no backlight
Hi, I had this same problem on philips 50pft5100, I would like to know how this problem is solved. Please let me know, thank you.Comment
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Re: Phillips TV no backlight
No idea, the OP quit...yet ANOTHER eternal mystery.
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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... -
Hello, got an iPad Pro A2378 12.9 5th gen with no backlight. Got another test unit without screen, tested the screen, still no backlight with the test unit.
Figured out the backlight on the screen was bad, ordred a new backlight from mobilesentrix, *carefully replaced it* without damaging the lcd, oh well.
Final result, issue is still there, the screen has no back lights. So i'm back to square one, with 3 hours less and 100$ out, issue still on the screen.
The panel is still ok, i can see the apple in the middle of the screen when it kicks in, just no backlight.
Anyone... -
TCL 75S421
PSU BOARD: 40-L402H8-PWD1CG
it shows not even a flash of backlight when powering up.
but the tv appeas to turn on and i can hear the sound of the menus moving and clicking. i can power down the tv with the button.
testing the backlights with my tester all 4 strings lit up and showed similar voltage drops. around 110 or so.
unplug mb and leave only psu plugged into backlights (PSU + BL SELF TEST MODE?) does not light the backlights.
i do see 24v but 0v on PSON and BLON (i didnt write this down tho so cant be sure)
with mb connected, PSON... -
Hello Team,
I'm back with another backlight issue that I thought was simple, but it turned out to be more complex than expected.
Let me provide a brief history: The TV was working well, then one day, the backlight started and shut down. I thought I had an LED issue leading to this behavior, so I replaced the LEDs with brand new ones. However, the issue remains the same.
Next, I replaced the electrolytic capacitors attached to the LED power supply, but the results were the same. I then replaced the driver, a OB3365RP, and did it twice due to the same result....
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