LG 43UF640V half picture

[london-freddie]

hi all, help advice needed please if anyone knows
been given this LG tv, it was going to tip, owner has far to much money and went and bought a new tv
when powered up it gives a picture as in the photo ie: half the screen perfect other half has a picture but is shaded.
changed the tcon board thinking that was its problem but no change in picture
swapped tcon ribbons same no change
any ideas please,
I am not at home till next week so can not send pics of internal boards till I get home
thanks

[london-freddie]

Re: LG 43UF640V half picture

think this must be also a picture of the tcon as it was next to the screen picture on my phone, so would have been taken at the same time

[diif]

Re: LG 43UF640V half picture

Perhaps something on the PCB attached to the TCON has failed.

[tiku]

Re: LG 43UF640V half picture

I Had the same problem with my panasonic ,too much carbon on the Tab Bonding On the Panel, Try to clean the tabs connected on the shaded side with an Eraser, hope your problem will be solved.

For Example.
See the Exact Area in The Pics.

[london-freddie]

Re: LG 43UF640V half picture

will check that next week when back home, thanks

[london-freddie]

Re: LG 43UF640V half picture

ok had a look at tab bonding all looks ok, pressing on all tab bonds whilst tv is on makes no difference to picture,
this seems to me a tcon board problem ??? maybe my used replacement is also bad ???
can i connect left side ribbon from the tcon to the right side of the screen to see if right side of screen then works as it should, or is that a dodgy move, or maybe try and get another tcon board

[diif]

Re: LG 43UF640V half picture

Have you checked the capacitors on the PCB for shorts ?
I take it you know the cable is not located properly in photo 1 ?

[london-freddie]

Re: LG 43UF640V half picture

hi thanks for that yes cables are located properly, not sure which board caps you are meaning, do you mean tcon board caps or screen driver board ?

[london-freddie]

Re: LG 43UF640V half picture

just ordered another tcon board (used),

[diif]

Re: LG 43UF640V half picture

hi thanks for that yes cables are located properly, not sure which board caps you are meaning, do you mean tcon board caps or screen driver board ?

Photo 3, the thin pcb that's attached to the screen. Doubtful your replacement tcon also had the original fault.

[london-freddie]

Re: LG 43UF640V half picture

no not checked caps on that board, will try and check them now

[tiku]

Re: LG 43UF640V half picture

I think your original T-Con is OK, But seems very dirty, it need a Good Bath in Ultrasonic Cleaner. Get it cleaned,it will work again.

but do check first with swapping the LVDS Cable, if the shaded side changes then certainly its a faulty T-Con.

Hey your LVDS Cable is not connected properly.

[london-freddie]

Re: LG 43UF640V half picture

caps on screen driver board seem all ok ie: no shorts on caps

[london-freddie]

Re: LG 43UF640V half picture

just cleaned tcon board with electrical contact cleaner, refitted tcon tv picture 100%. great, However after a few minutes reverted back to half screen perfect other half working but shaded

[london-freddie]

Re: LG 43UF640V half picture

working, not for long though, back now to half screen

[tiku]

Re: LG 43UF640V half picture

It surely needs a thorough cleaning,because mere cleaning with contact cleaner will only do a surface cleaning, where as it need cleaning below the smd's also.

[london-freddie]

Re: LG 43UF640V half picture

i have no no ultrasonic cleaner

[london-freddie]

Re: LG 43UF640V half picture

going to try heat on tcon board, after cleaning I dried it on a radiator maybe board was warm when I refitted it and it worked

[london-freddie]

Re: LG 43UF640V half picture

just warmed tcon board, no change still half picture, will have to wait for this next replacement tcon to arrive

[tiku]

Re: LG 43UF640V half picture

Ok take a soft toothbrush and a detergant powder or liquid, make a lather in a tub or a bucket, and dip T-Con in it,clean thoroughly with a toothbrush for atleast 10-15 minutes,front and back side, after that wash it under running tap water, with pressure so if there is any corrosion beneath the smd;s, it gets cleaned, then after that if you have 99% Isopropyl alcholol Solution, Dip in it for 1-2 minutes, or pour on it, so that it dries out water from T-Con, then Dry T-Con with Hair Dryer, keep it aside for atleast 10-15 minutes, then dry again with hair dryer if you are not sure if all the moisture is dried out, then you can re-connect T-Con.