My tv wont turn on
Power board
Main board
My LG 42LD520-UA has the red standby light when its plugged in .
But the tv will not power on .
What can i do to fix this?
Questa è una buona domanda?
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@hazardus sounds like a power board issue. Unplug your set and disassemble it. Than take a look at the boards, in particular the power board. Check for leaking or domed looking caps. Post some images of your boards with your question. Use this guide for that. It will allow us to see what you see.
Also, make sure that it is not your backlight that is out. Turn your set on, darken the room and use a flashlight angle the beam at the display and see if you can make out any shadows etc. Let us know what you find.
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I have already checked the electrolytic capacitors and othe component of the power board and all are ok and none have been found deffective . But i will try the backlight check because i did not try that.
And when the tv in plugged in i do have the red standby light at the bottom right hand corner .but dosent turn bleu when i press power button.
I will post pictures for you to see my power and main board.
and i was using your guide that you put in your awnser . And all is ok until i get to the X1002 clock because i do not have the meens to check frequency .
Try resetting the TV (unplug the tv hold the power button down for 10 seconds then plug it in while the power button is pressed.)
I am getting power to the power board but my TV is not turning on at all
I tried to reset my tv but it still want come on
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What make and model TV? What do you mean by reset? What have you checked? What does your TV do or does not do?
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@oldturkey03 thanks for the guide but on my 47LD450 there's no standby light so I wonder if you got a guide for my case.
The power button does nothing. After unplugged for several days, the TV goes on for a few seconds and then goes off for days.
I checked capacitors, replaced some in secondary circuit. No help.
There's +3.5V at 4 pins on the connector to the mainboard, but no +12V or so. While there's +12 on two large capacitors next to the connector.
When I check voltage on the second wire jumper from the connector and I touch it with the probe, the backlight goes on for a few seconds but then goes off. If I touch again after a few seconds - it happens again.
Perhaps until the TV is not turned on by the button, it is OK that there's no +12 on the connector? Or it should be there anyway?
Why do I have +3.5 but no standby light? Is this because the PSU or because of the mainboard?
So I wonder what to buy- the PSU or the mainboard? Could you advise pls?
da Uri Lukas
@uri_lukas No standby is usually an indication of a bad PSU. That could also explaining the voltage issue.
da oldturkey03
"No standby is usually an indication of a bad PSU."
- Thanks @oldturkey03 .
Yes, usually it is a bad PSU. It's just in these TVs the voltage for power button and for standby light both go through the mainboard, which has several triggers to control the PSU, like to switch it to the sleep mode, etc.
I just wanted to be sure that 'no standby light' means a bad power supply.
Because on Internet you could find many similar cases, where people would replace the PSU one or more times without luck.
Thanks again.
da Uri Lukas
@uri_lukas you are right but it's the power board that would have the standby voltage. No standby voltage PSU no good ;-)
da oldturkey03
Well, I do have +3.5V....
https://youtu.be/EQ4hWflmjEw
da Uri Lukas