KDL-40NX800 lines in half screen!

[Andreasbest]

Hello fellow technicians and happy easter.
Today a Sony Bravia KDL-40NX800 arrived and according to customer due to weekend and without any use produced lines in half screen.
Unfortunately no service manual or diagrams (for free or sale) for this set so i'm kinda "blind" and hoping for your help.
Check pictures of all boards and the fault it self.
What do you think?

[budm]

Re: KDL-40NX800 lines in half screen!

Panel problem.

[CapLeaker]

Re: KDL-40NX800 lines in half screen!

gets my vote too... toasted panel

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

So directly to recycle?

[freakaftr8]

Re: KDL-40NX800 lines in half screen!

Oh it's got that infamous sharp tcon board. I have my doubts on the panel being bad now. Try heating up the tcon board especially around the main processors. Watch for picture change

[Davi.p]

Re: KDL-40NX800 lines in half screen!

For me it's not serious to attempt a long distance diagnose, until you don't provide how the image in your picture is came up, i.e. if you post the same source signal on a good tv (if any there was), and if you explain why an half of screen is black, is due to a disconnected cable? If not i would say a bad FPC on the black half, not full repairable but pressure on FPC can help, if yes there's something could be done to repair it (FPC masking on tcon output).. anyway seems a panel problem.

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

No source at all, i just turn on tv and on all inouts produce this.
Half screen is black because i have no input as i said.
All cables look intact and tight.

[Davi.p]

Re: KDL-40NX800 lines in half screen!

You can make the common test to detach one (if there are two, if not 2) tcon output flat cable at a time and see the image (post it).

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

Oh it's got that infamous sharp tcon board. I have my doubts on the panel being bad now. Try heating up the tcon board especially around the main processors. Watch for picture change

Ok found the issue.
The IC i marked with red below nand it's the one responsible for the helf right scrren needs reballing/reflowing, after very little heating starts to work as it should.
Now i have reflow it 3 times already and gonna do it one more time tomorrow, then i'll assemble it and test it for some hours.
Thank you very much all and especially freakaftr8 and his idea, i would have waste it already without him

[freakaftr8]

Re: KDL-40NX800 lines in half screen!

Good to hear I've had this problem 3 times with 3 different TV's ranging from 46 to 52 inch. All use this tcon. And all were NX800 models. I have successfully reflowed one out of all three that I have tried to repair. This seems to be a tricky board for re flow. It may take for a while but then it will go again. The IC really needs to be reballed instead of reflowed.

Glad you found the issue.

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

I'll try with reflowing because cost of reballing is above cost of another tcon.
If no luck then new tcon

[Davi.p]

Re: KDL-40NX800 lines in half screen!

I've heard of some repairs where a simple reflow with hot gun/air station will not last, it is needed a cooking on oven...

[peterkos2]

Re: KDL-40NX800 lines in half screen!

Hello everyone.
I also have a problem with the SONY KDL-40 NX 800 TV. The belts were running on the screen and I also heated the main chip with a heat gun and the belts got lost. The TV went nice but the next day after a while the same thing happened again. I also have a hot air station - how many degrees should I heat it up? Or then at what temperature to cook in the oven?
Thank you for your response

[Diah]

Re: KDL-40NX800 lines in half screen!

275° for whole life

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

Be aware that no matter what you do it will occur again and sooner.
The problem is lack of thermal protection (small heatsinks), even if you replace mainboard it will occur again

[peterkos2]

Re: KDL-40NX800 lines in half screen!

Thanks for the answers.
I must say that I also removed the silicone heat-conducting pads, because oil was precipitated on them.

[Andreasbest]

Re: KDL-40NX800 lines in half screen!

If possible add larget heatsinks.

[peterkos2]

Re: KDL-40NX800 lines in half screen!

Should I buy new thermally conductive silicone pads ?. Can they release oil after heating because they are old? They are about 10 years old on this TV.
Only the second time the fault was repeated shortly after turning on the TV.
well thank you

[peterkos2]

Re: KDL-40NX800 lines in half screen!

Can the leaked oil from the thermal pad cause any image distortion?

[nomoresonys]

Re: KDL-40NX800 lines in half screen!

Maybe clean it up and replace those leaky pads for sure.