Vertical Coloured Lines Samsung 40" LE40R74BD LCD

[StephenU]

Good Afternoon all,

Got my hands on a Samsung 40" LCD HDTV Model number: LE40R74BD, the screen has Vertical coloured lines all over. (History of unit unknown)

Opened unit and gave it a good check over - PSU had been previously repaired (Few caps changed) and noticed another 2 needed changing (Both swelled - 1000uF 25v x2)
Upon taking the PSU out of the unit to replace I noticed burn marks on the rear of the panel,turns out one of the Transformers
looks to have shorted to the rear of panel.

Changed the 2 swelled caps and redone the solder joints on the previous cap replacements.

I have inspected the boards all over and can see nothing else obvious.

Mounted some new standoffs to make sure there where no way of the tranny to short again! (Also stuck some Capton tape on the rear of the screen where short had occurred.)

Tv still displays the same Vertical coloured lines all over.

Powers up with little start up tone then lines appear - Does anyone know if the panel is gone? (Pics to follow)

Any help/guidance would be much appreciated, oh and amazing forum by the way! (First thread..!!)

[StephenU]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

'Rainbow Effect / Coloured Vertical Lines' >>>

[StephenU]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

Anyone came across this issue before?

TIA

[mmartell]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

Ooh that's ugly lol. The two black areas make me think the panel is toast.

[selldoor]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

I would sya the panel has likely gone but it could be the tcon or the cables that
fo to/from it- try reseating them or see if it changes if you press on them.
Check any voltage regulators on the tcon.

[tom66]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

I have seen a similar, but slightly different fault on this model before (only a few vertical lines with no image at all), which was caused by a bad voltage regulatos on the T-con board.

Failing that I would agree with bad panel.

[StephenU]

Re: Vertical Coloured Lines Samsung 40" LE40R74BD LCD

Thanks guys just read your fix on the 2.5v LDO reg on a similar unit tom66. Sometimes the two bold dark lines disappear making me think the panel 'might' still be ok, going to go over it again tonight check all regs on the T-Con, failing that I have found a replacement T-Con for buttons.
Will report back any findings later tonight or tomorrow.

Thanks