Bush DLED32287HDCNTDFVP led smart tv screen not turning on

[ioanban]

Hi,
Problem: TV screen has no picture at all , I can't see any thing, all black.

The TV's backlight is working (tested with led tester), I have changed the motherboard (tried 2 of them but the same no picture). I have measured the Voltages on the power board ( you have them in one of the previous posts), i have stand-by light when plugged in .

[dick_barton]

The led tester is useful but is not a definative test due to the fact that only a low current is fed to the leds.
Do the leds flash when you come out of standby?
What voltage do you have on the led output connector at switch on?

What is the dc voltage on pin 16 and on pin 5 of U2 (MAP3249)

[cheeky2]

For people to help you and guide you need to give as much information as you can so that they can try to guide you in the right direction for resolving your issues.
Without full information from your answers then you will take longer to get to your resolution if that is possible.
First off I would suggest you remove the led power connector and place your led tester across the leds to power them on independently without the power from the TV's power supply.
Then power on your TV and see if you get a picture on your TV. If you get a picture then clearly one or more of your leds could have failed or your power supply is faulty.
Let us know what your results are, as they will indicate where the issue lies.

[ioanban]

The LED's don't flash at all when coming out of standby.
On the led output connector at switch on i have 30V.
I can't find any U2 (MAP3249)

[ioanban]

The LED's don't flash at all when coming out of standby.
On the led output connector at switch on i have 30V.
I can't find any U2 (MAP3249)

[ioanban]

Originally Posted by cheeky2

For people to help you and guide you need to give as much information as you can so that they can try to guide you in the right direction for resolving your issues.
Without full information from your answers then you will take longer to get to your resolution if that is possible.
First off I would suggest you remove the led power connector and place your led tester across the leds to power them on independently without the power from the TV's power supply.
Then power on your TV and see if you get a picture on your TV. If you get a picture then clearly one or more of your leds could have failed or your power supply is faulty.
Let us know what your results are, as they will indicate where the issue lies.

Hi,
I have done exactly as you have told me but i still don't get any picture .
I have given all the information I had and as much as i could get every time. I do apologise if you think I'm not paying attention to what I'm being asked.

[dick_barton]

Post some photos of the top and underside of your power supply.

[cheeky2]

The string of leds that light your TV screen up will have a higher voltage than 30V. The Led voltage string is measured with reference to the ground of the TV. So place one probe on the metal chassis of the housing and one on one of the two connections for the led power connector. Measure both voltages.
Though from what you have said so far I would suspect a faulty screen.
Use a scart device to check the main board by connecting up a fully wired scart lead to a vhs player or a dvd player. Put the scart device that you have connected to the TV into standby. Now turn on the TV from standby give a few moments to initialise the TV then turn on the scart connected device from standby to on. Play the media you have for the scart connected device ( ie vhs tape on vhs recorder ensuring that the media has audio coming out) or play a cd on the dvd player. If your main board is good then you should get audio and should be able to adjust volume with remote control and mute it. The scart lead will switch over automatically to the scart connection without any interaction of the remote control.
If you get audio then I would say your main board is good.

[ioanban]

Originally Posted by dick_barton

Post some photos of the top and underside of your power supply.

Picture attached. Everything seems to be ok.

[ioanban]

Originally Posted by cheeky2

The string of leds that light your TV screen up will have a higher voltage than 30V. The Led voltage string is measured with reference to the ground of the TV. So place one probe on the metal chassis of the housing and one on one of the two connections for the led power connector. Measure both voltages.
Though from what you have said so far I would suspect a faulty screen.
Use a scart device to check the main board by connecting up a fully wired scart lead to a vhs player or a dvd player. Put the scart device that you have connected to the TV into standby. Now turn on the TV from standby give a few moments to initialise the TV then turn on the scart connected device from standby to on. Play the media you have for the scart connected device ( ie vhs tape on vhs recorder ensuring that the media has audio coming out) or play a cd on the dvd player. If your main board is good then you should get audio and should be able to adjust volume with remote control and mute it. The scart lead will switch over automatically to the scart connection without any interaction of the remote control.
If you get audio then I would say your main board is good.

That's exactly how i took the measurements!
The main board, i have previously said that i had it replaced it and i still haven't solved the problem !

[dick_barton]

Disconnect the led connector and use you led tester to power up the leds and switch on your set and see if you have a picture.

[ioanban]

Originally Posted by dick_barton

Disconnect the led connector and use you led tester to power up the leds and switch on your set and see if you have a picture.

I've tried before, i got no picture .

[dick_barton]

If there is an smd fuse on the panel strip, have you checked it

[ioanban]

Originally Posted by dick_barton

If there is an smd fuse on the panel strip, have you checked it

yes, there's one and it's ok

[ioanban]

Originally Posted by dick_barton

I have just reread your first post and I am not too sure what the problem is.
You say you the backlights are OK. Are they coming on but there is no picture.
You have also changed the mainboard and you still have "the problem".

Can I ask once again for a detailed description of what is and isn't working.

you have said it as well. I have power, I have replaced main board, I have verified the backing light, there is nothing wrong with them and I still have no picture in the screen !
I'm thinking that the panel is gone.

[cheeky2]

Originally Posted by ioanban

That's exactly how i took the measurements!
The main board, i have previously said that i had it replaced it and i still haven't solved the problem !

But you failed to say whether you get audio or not? Changing a main board doesn't necessarily mean that the main board is good. If you have a different main board which uses a different screen combination then you can quite easily get backlights but no screen display. Did you realise that?
Main boards can be programmed up for different screen combinations and are often done so in the same model of TV when the manufacturers get different screens. So purchasing a main board for a TV based on the model number of the TV isn't advisable and can give you exactly the symptoms you describe.
Often sellers on ebay have no clue about this!
Though in all probability your screen is goosed!

[ioanban]

Originally Posted by cheeky2

But you failed to say whether you get audio or not? Changing a main board doesn't necessarily mean that the main board is good. If you have a different main board which uses a different screen combination then you can quite easily get backlights but no screen display. Did you realise that?
Main boards can be programmed up for different screen combinations and are often done so in the same model of TV when the manufacturers get different screens. So purchasing a main board for a TV based on the model number of the TV isn't advisable and can give you exactly the symptoms you describe.
Often sellers on ebay have no clue about this!
Though in all probability your screen is goosed!

I'm sorry for omitting to say that I did get sound with an dvd player but no picture.
when I'm ordering parts for tv's I'm always making sure they have the same part number, I know that same model tv can have different boards .

Thank you,