Lg 60uf770v 4k screen problem

[daz2206]

firstly i would like to say what a fantastic forum this is, i dont like to bother people and for over 3 years ive managed to fix most tv's just by reading this forum but im stuck on this one,
Im hoping someone might be able to help me with this tv, im assuming its the mainboard at fault (already swapped the tcon and theres no difference, i contacted lg hoping to buy the mainboard who sent me to equinox who told me the tcon was the problem but it is part of the screen so they want £1336.52 to fix it :-( (tcon is not part of the screen and ive already tried another tcon) unplugging one tcon cable sends tcon into the test screen (red/blue/green/white) which looks perfect, the faulty side can be either grey or bluey green and flashes rapidly (strobe like) backlight is steady looking from the back throught the holes so not an led problem, picture is perfect behind the grey/blue flickering, ive attached a few pics hoping someone might know what the problem is
thanks in advance darren

[freakaftr8]

Re: Lg 60uf770v 4k screen problem

That's an interesting one and considering that there's 2 LVDS cables I may be opted to say that there is a malfunctioning LVDS cable. Especially since your T con shows perfect uniform pictures with no abnormalities. I suppose given the design could be a mainboard problem too. have you tried heating up components on the main board?

[daz2206]

Re: Lg 60uf770v 4k screen problem

No i hadnt thought of heating parts up on the mainboard. I did try reconnecting all the cables and pressing on connectors but it made no difference. Il try a little heat on it tomorrow though. Thanks

[daz2206]

Re: Lg 60uf770v 4k screen problem

tried some heat on the mainboard and the flickering stopped but still had the grey half screen, (when it cooled it started flashing again), ordered some new lvds cables as i accidentally melted one while trying to watch the screen while heating the board so il see if the new cables makes any difference.

[Davi.p]

Re: Lg 60uf770v 4k screen problem

I say: why in your pictures it miss the blue screen by self test? It surely must be there.. Its evident there's a problem with blue subpixels as they seems are always on. Since the tcon is on the bottom i suppose someone have washed the screen like a funny window or mirror... :-( so you must dismantle the screen bezel to show probably a corrosion on some connections.. bye..

[daz2206]

Re: Lg 60uf770v 4k screen problem

sorry it does show the blue test screen fine too, i just didnt upload it to the forum, im hoping the lvds cables will arrive tomorrow so i can rule them out, pretty sure its either the cables or mainboard as it did make a difference with heat on the mainboard.

[Davi.p]

Re: Lg 60uf770v 4k screen problem

Lets hope maybe from main to tcon there are separate signals in them for the two half of the screen, this in 4k tv only i think.

[tom66]

Re: Lg 60uf770v 4k screen problem

I would say that this is probably a bad LCD panel, unfortunately, given your diagnosis so far.

I would also try unplugging one ribbon from the T-con board at a time.

[daz2206]

Re: Lg 60uf770v 4k screen problem

ive just received the cables this morning so il fit them tonight and see if it makes any difference, warming the mainboard did stop the flickering so im really still hoping for a mainboard fault (not that im having any luck whatsoever sourcing one)

[maxvalutech]

Re: Lg 60uf770v 4k screen problem

A similar problem I had was one of the two cables from t-con to the screen and they went inside a small slit in the metal framework so basically unfixable in that case.

[daz2206]

Re: Lg 60uf770v 4k screen problem

ive found a mainboard in spain so if it doesnt fix the problem it can only be a bad panel :-(

[Davi.p]

Re: Lg 60uf770v 4k screen problem

Why don't you see under metal bezel for corrosion?

[daz2206]

Re: Lg 60uf770v 4k screen problem

Why don't you see under metal bezel for corrosion?

i took it off when i fitted the tcon cables and all looked good (tried pressing on the lcd ribbons etc too), i also tried disconnecting each lvds and both sides show similar images so still hoping the mainboard is the problem, each time i mess with it the bad half shows a different hint of colour, (pink,grey,green,blue)

[Davi.p]

Re: Lg 60uf770v 4k screen problem

Have you tried a service menu reset?

[london-freddie]

Re: Lg 60uf770v 4k screen problem

does this have the same problem as the tv on my post ??? I think it has

[daz2206]

Re: Lg 60uf770v 4k screen problem

Have you tried a service menu reset?

No, i can try tomorrow though

[daz2206]

Re: Lg 60uf770v 4k screen problem

does this have the same problem as the tv on my post ??? I think it has

Yes same fault exactly i think

[london-freddie]

Re: Lg 60uf770v 4k screen problem

any luck in fixing your tv yet, still no luck with mine, it must be main, tcon, ribbons or panel, BUT which ?????
after 3 tcon boards in mine I should rule out the tcon, but does seem like a tcon problem to me, maybe the fault is coming from the mainboard though.
It would be easier to fix if it was just dead

[Davi.p]

Re: Lg 60uf770v 4k screen problem

I wonder if is possible to swap signals destinated to one half to the other one, but in a enough easy way, since swapping of flatcable position result in a sure damage, maybe is possible to find out color signals, mask them all apart 3-4 and swapping them between sides with a soldering between tcon and panel, this is to ensure the defect is on the colour lines and if the defect travels then tcon fault, if not panel fault... Compris?

[budwich]

Re: Lg 60uf770v 4k screen problem

I quickly look thru both "related threads" that the two gentleman are "running". I guess my comments / questions deal with some of the observations and details around those.
Some mention "disconnecting tcon cables made no difference"... but which cables exactly did you disconnect and where and exactly what was a "pictured result" (post photo).

Further with respect to this thread, at the start, the OP disconnects "one of the tcon cables" (which one???) and indicates that the set goes into some form of display test screens. What cable are you referring to ... and does it happen with others disconnected?

Somewhat related, but what types of signals have you been feeding the set versus the pictures that you have shown? Lastly, on this set, is there any "unclampable cables" at the edge boards along the panel that allow you to gently disconnect boards further in the signal path?