samsung ue55nu7021k backlights working but blank screen

[lotas]

Re: samsung ue55nu7021k backlights working but blank screen

HDMI may also fail with EDID (Extended Display Identification Data) corruption.

[lotas]

Re: samsung ue55nu7021k backlights working but blank screen

So on odd occasions I could get inputs to works, could only switch via the buttons on the tv itself but whilst i got picture, got no sound.

Sorry can I ask what you mean connected too HOT?

Connecting HDMI to "hot" is when the TV is connected to the AC power (inserted into the socket), the Internet network cable is inserted and you connect another device via HDMI, which is also connected to the AC, a static discharge occurs in the HDMI jack and the protective diodes, controllers, processor burn out ...
Always first you need to connect HDMI, first of all, then the Internet cable and lastly connect to the AC (insert into the socket)
And turn off HDMI last.

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

Would this be the same one as well?

https://www.electromix.co.uk/main-pc...8240-wx2a.html

yes if it was me i would take a chance on buying it (but only you can make the decision buying it as may not solve the fault) i have just seen your post lower down good you managed too get it showing a picture again not sure whats causing that error message.

lotas may know could a faulty tcon cause this as its a picture setting issue?

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

If his inputs do not work and there is no sound, then most likely the HDMI inputs are disabled (something was connected to "hot").

So just checked this once again and managed to get the fire stick on the HDMI port displaying. Although the round circle suggesting its thinking keep constantly coming as well as the message as per the photos. I've also uploaded a video (zip file) to show how its constantly cycling between the screen, then get the thinking circle and then the message after-which your back to the display from the input.

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

If his inputs do not work and there is no sound, then most likely the HDMI inputs are disabled (something was connected to "hot").

So on odd occasions I could get inputs to works, could only switch via the buttons on the tv itself but whilst i got picture, got no sound.

Sorry can I ask what you mean connected too HOT?

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

The only place i can find with that exact board is out of stock so maybe a common issue https://www.tvparts.co.uk/lcd-tv-spa...7021kxxu-ver02

Would this be the same one as well?

https://www.electromix.co.uk/main-pc...8240-wx2a.html

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

yoda79
can you take a clear picture of this white sticker too many thanks

Ok so this is on the mainboard ( the green one), does this help?

The number is BN94-12869M

[lotas]

Re: samsung ue55nu7021k backlights working but blank screen

If his inputs do not work and there is no sound, then most likely the HDMI inputs are disabled (something was connected to "hot").

[diif]

Re: samsung ue55nu7021k backlights working but blank screen

Does applying heat to the processor with a hairdryer/hot air make any difference ? I wonder if it's a BGA issue.

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

The only place i can find with that exact board is out of stock so maybe a common issue https://www.tvparts.co.uk/lcd-tv-spa...7021kxxu-ver02

[lotas]

Re: samsung ue55nu7021k backlights working but blank screen

Lotas when ordering a replacement main board which numbers do we use? im still learning myself i usually use the bn number (model bn41-02262) plus the cy-nn055hgev8h lcd panel number is this correct?

If you order the mainboard for a specific Samsung model, then you need to use the number
"BN94-XXXXXX"
For example:

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

Ok I think I've attached the photo of what you mean. It says BN95-05414Q?

Do you think the board will be faulty, would the picture come on then? The picture test does work but inputs don't work nor is there any sound?

Also what board at the back do you think needs replacing?

inputs and sound all go through the mainbord as you cant update it either the next step is too try a replacement in my opinion unless more experienced members can advise us better.

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

Lotas when ordering a replacement main board which numbers do we use? im still learning myself i usually use the bn number (code bn41-02262) plus the cy-nn055hgev8h lcd panel number is this correct?

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

Mainboard

yoda79
can you take a clear picture of this white sticker too many thanks

[lotas]

Re: samsung ue55nu7021k backlights working but blank screen

Ok I think I've attached the photo of what you mean. It says BN95-05414Q?

Do you think the board will be faulty, would the picture come on then? The picture test does work but inputs don't work nor is there any sound?

Also what board at the back do you think needs replacing?

Mainboard

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

Ok I think I've attached the photo of what you mean. It says BN95-05414Q?

Do you think the board will be faulty, would the picture come on then? The picture test does work but inputs don't work nor is there any sound?

Also what board at the back do you think needs replacing?

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

on your first picture lower edge can you take a picture of the white sticker that says samsung on it so we can see what lcd panel number it uses thanks (on ebay the mainboards are averaging £35.00 so up too you if you want too take a risk replacing it)

https://www.ebay.co.uk/sch/i.html?_f...662A&_osacat=0

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

so that went better than I expected! I have got the back off and photos attached of whats there. Any thoughts? Can get better photos if you need.

[Yoda79]

Re: samsung ue55nu7021k backlights working but blank screen

https://www.youtube.com/watch?v=oNqJppoV5S0

Great thank you, sorry been super hectic at work so trying to find time has been tough. Video is good thanks, just need to find something like the Smudger he uses.I'm guessing something semi hard but of rubber would be ideal.

[vinceroger69]

Re: samsung ue55nu7021k backlights working but blank screen

Great thanks. Do you think you can use a flat screwdriver for this?

https://www.youtube.com/watch?v=oNqJppoV5S0