Seiki SE421TT LCD - powers on, but has no backlight
I'm working on this Seiki brand 42" LCD TV and it powers up, but doesn't light the backlight or anything. Any ideas as to where to start the troubleshooting process or what could be causing this issue in here?
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Re: Seiki SE421TT LCD - powers on, but has no backlight
You'll more than likely have an open led.
what voltages are there going to the leds? -
Re: Seiki SE421TT LCD - powers on, but has no backlight
What are the terminals labeled that usually feed leds?Comment
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Re: Seiki SE421TT LCD - powers on, but has no backlight
Ahh umc crap, is the blon voltage present possibly epprom if not bad led ?Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !
https://www.facebook.com/Telford-Tel...7894576335359/Comment
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Please Do Not PM My Page Asking For Help Badcaps Is The Place For Advise, Page Linked For Business Reasons Only. Anyone Doing So Will Be Banned Instantly !
https://www.facebook.com/Telford-Tel...7894576335359/Comment
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Pictures
I have taken pictures of the mainboard, T CON, and power supply. As for checking that voltage, where would I need to test to find that?
(badcaps.net attachment uploading is giving an error right now, pictures are hosted on TinyPic instead)
Mainboard Left: http://tinypic.com/r/21lia/8
Mainboard Right: http://tinypic.com/r/2n6fehd/8
T CON: http://tinypic.com/r/w1v5ua/8
Power supply top: http://tinypic.com/r/24mglrl/8
Power supply bottom: http://tinypic.com/r/30xbt07/8Comment
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plan of action
Any updates on this? Should we try replacing the mainboard first and go from there?Comment
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Re: Seiki SE421TT LCD - powers on, but has no backlight
https://www.badcaps.net/forum/showthread.php?t=41789Comment
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Never stop learning.
Just to follow up on this, even though it has been a while, I don't think we were able to get this one going. The happy ending is that I think we were able to sell it on behalf of the owner and at least partly make up for the losses. Knowing what I now know about Led backlight repair from recent experience and what was shown in the other thread, I bet that is what the problem might've been though.
Don't stop believing - never stop learning.Comment
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this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even... -
Hello, I have an "ASUS ROG Strix G713QR" laptop, and for approx. 3 months I have the following problems:
1. Laptop keyboard doesn't work
2. The backlight on the laptop keyboard doesn't work
3. The x2 side LEDs (red) on the laptop don't work
The power button works, the touchpad works, and all the USB, HDMI, Ethernet, etc. ports work.
I already tried to reinstall all the drivers and reinstall Windows. So I don't know what to try anymore that is software-related.
But I am strongly aiming that it is somehow a BIOS-related problem,... -
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This TV recently went through some 'death throes' and now won't boot. The first problem that began to manifest was while watching tv, the screen would 'freeze', and the image would dim over a few seconds until it was very dark. HOWEVER, the audio of the show would continue as normal. I could power off the TV for 5-20 seconds, power back on, and the video would be normal. This would occur 1-3 times when the TV was first started, and would not happen again after the TV was 'warmed up'. Not ideal, but this glitch was manageable.... -
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...
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