LG 42ln5300-UB won’t turn on and only has standby voltage

[NickIsFluffy]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

You still did not perform the test as requested in post #21, #31. You are not doing what we are requesting to help troubleshooting the problem. We are up to 39 posts now and still no result for us to see.

If we think logically my mainboard and powerboard doesnt not have an issue. I already said that we replaced the mainboard and the power supply board. so it shouldnt be an issue.

[NickIsFluffy]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

My next suspicion is that this standby LED card may have something to do with it because when I press the on button on the control buttons, it's supposed to give a signal to the main board to do whatever you are telling it to do. But that's not happening and neither is there a standby LED

[budm]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

P201 is the connector where you had tested the 12V, 24V, PWR-ON earlier, make sure to count the pins correctly. Make sure to count the pins correctly, the black dot is pin 1, the exposed pins that you can see from the top of the board are the EVEN number pins, to get to the EVEN number pins you will have to probe from the backside (this is harder to do because you have to flip the board over and the power is apply, more chance of shorting things out) of the board or probe at the wire entrance of the connector. BTW, all the connectors have to be put in place for this test.

[budm]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

If we think logically my mainboard and powerboard doesnt not have an issue. I already said that we replaced the mainboard and the power supply board. so it shouldnt be an issue.

So you are 100% sure that those two board are perfectly good boards and no way the used boards can be bad? We are trying to verify them by checking the Voltages. Good luck figuring out, I am out.
You say the new boards have no issue but yet you are not getting the PWR-ON to turn on the rest of the power supplies. Is that logical that there is problem??? Right now we have no idea what control signals you have or do not have from the main board when power switch is toggle on and off.
You can keep throwing in new boards at it and hoping it will fix the problem or perform troubleshooting step by step..

Your post # 12"

Quote:
Originally Posted by R_J View Post
The board outputs for a (42") 157.5v/ 341ma I agree he has an open led string.
You use a meter to check the voltage on the PWR-ON pin when you push the power switch.
When I test it, it just shows 0.

[nomoresonys]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

FFS, just buy a new tv, I'm afraid you will be 150 years old before you fix this one, you need a little competence to work on electronics, There are DEADLY voltages that I don't think you should be around. Give this tv to someone who can fix it...and just let it go.

[NickIsFluffy]

Re: LG 42ln5300-UB won't turn on and only has standby voltage

So you are 100% sure that those two board are perfectly good boards and no way the used boards can be bad? We are trying to verify them by checking the Voltages. Good luck figuring out, I am out.
You say the new boards have no issue but yet you are not getting the PWR-ON to turn on the rest of the power supplies. Is that logical that there is problem??? Right now we have no idea what control signals you have or do not have from the main board when power switch is toggle on and off.
You can keep throwing in new boards at it and hoping it will fix the problem or perform troubleshooting step by step..

Your post # 12"

Quote:
Originally Posted by R_J View Post
The board outputs for a (42") 157.5v/ 341ma I agree he has an open led string.
You use a meter to check the voltage on the PWR-ON pin when you push the power switch.
When I test it, it just shows 0.

correct, the boards are perfectly fine