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info tech
info tech, Technician
Category: TV
Satisfied Customers: 15794
Experience:  Television Engineer for many high street outlets 20 plus years experience
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I have a Samsung 40inch Flat Screen Smart TV. Just under 3

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I have a Samsung 40inch Flat Screen Smart TV. Just under 3 years old.
Been faultless until last few days.
When viewing on a morning after about 10 mins the top 2/3rd of the screen goes slightly darker. Still get a picture but background is darker. Turn TV and Sky off for 5 mins and its OK but then re-occurs.
Weird thing is it doesn't happen later in the day?
Have checked Sky signal = no problem - Sky checked = say not a satellite issue.
As it is intermittent at specific time of day I thought may be Sky related but they say not?....any suggestions. Not under warranty and not sure where to call if I need a call out.
Hello my name is Anthony
Thanks for the Question
Have you rebooted by unplugging BOTH the TV and box from the wall waiting 5 mins then re-plugging back in?if not please do that and let me know if that changes anything
After you do that if its still the same try another input like DVD player is it the same using that?
Let me know please either way
Customer: replied 3 years ago.

15 minutes - problem has just reoccurred on all tv channels and same when I switch to dvd

Customer: replied 3 years ago.

15 minutes problem just reoccurred on all tv channels and dvd - help?

Hello Ian
Ian if you press the menu button of the sets own remote control is the menu dark too ?
Customer: replied 3 years ago.

no menu seems to be consistent colour all over

So switching back to a picture its dark top two thirds, the menu is consistently normal and bright, Ian I will need now to know the model number of the TV found on the back of the set?
Thanks let me know
Customer: replied 3 years ago.

Yes - the problem is NOT affecting the blue menu display

The Type is UE40D5520

Model Code is UE40D5520RKXXU

Version 09


Hello Ian
Ian the menu test rules out the power board the tcon board and panel also the LED back light so it leaves the mainboard as the issue the mainboard will need to be replaced do you think you can do this work yourself?are you "hands on" enough to get the back off the set find the board and replace it?I will provide more details on how to do that.
Otherwise an engineer will charge around £150 for this work depending on where the board is sourced.
Let me know if you can do the work (I will provide more details)
Please consider rating the answer positively, rating me positively enables me to receive credit from the site, thank you, ***** ***** will remain open and stay open as long as you need it, if you have any concerns please don't rate instead press the "reply to expert" tab and I will answer any queries you have
Many Thanks
info tech and 2 other TV Specialists are ready to help you
Customer: replied 3 years ago.

I have a very good friend who is an electrician - I am sure he can do what you suggest so if you could let me know what to do next I would appreciate it....


I am going out shortly so look forward to your suggestion and will get back to you tomorrow as required.


Thank you for your help. What is baffling is that this only seems to happen in the day and not (yet) at night when room lights are on?? = not sure if it is light on the screen related as sometimes in bright sunlight during the day


Thats great he will be ideal if you cant do it.

OK get the back off the set (be careful at all times with a set this big)locate the mainboard thats the one with all the AV connectors on, unplug the board (maybe take a photo before unplugging so you dont make mistakes later)then unscrew the board from the chassis.
Now you have the board out look for the part number on the board it should begin BN with this part number go to or or google the part number fitting is the reverse, their is no set up its just plug and play.

Let me know if you run into any difficulties

Thank You for rating and bonus !thats much appreciated

Thanks again Anthony, oh if you get back to me I may not be able to answer immediately but will when I see your post

Customer: replied 3 years ago.