Samsung UE46C800 Intermittent Vertical Bands

[Anachronist]

Hi there,

Our sterling UE46C8000 has recently come out of storage and has started intermittently exhibiting two vertical bands - one light, one dark - side-by-side to the left of the screen.

Sources are through a receiver so only using one input on the TV. Changing inputs makes no difference.

Often they will disappear on a scene change watching live material but with recorded material they'll stay until the input source is changed, or switched to menu/guide. Appears to be more prevalent with recorded material.
No vertical bands on the self test.

I can't find anything similar anywhere so if anyone's seen anything like this before I'd be very grateful to hear about it.

[Diah]

Re: Samsung UE46C800 Intermittent Vertical Bands

as it was in storage.. no one know what happen at time there ... so you need to open it and clean inside.. take out all cable specially the LVDS cable ( the one between the mainboards and t-CON) clean them and put them back in place.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

OK, Back off, vac'd out. It was pretty clean inside but was stored sealed inside its box.

All boards disconnected and inspected. No visible component damage or dry joints. Signs that mainboard and TCON board have got warm at some point - staining underneath both on the chassis.

All sockets blown out with canned air and plugs/ribbons/grounds cleaned with isopropyl.

Back together and.... banding is back after 5-10 minutes. Goes away switching between sources as before.

What now - hunt for some boards or find somebody locally with an oscilloscope?

[Davi.p]

Re: Samsung UE46C800 Intermittent Vertical Bands

CLeaning totally unuseful in theese cases, you have problem with the specific source driver, locate the COF in corrispondence of the fault, then inspect the board attached to it, if there's no corrosion, then the cof is partially desoldered, must use soldering iron tip on to he back that is the side in front of you under the chip, must be put something rigid but not heat transmittant under it to be able to press it well..

[Diah]

Re: Samsung UE46C800 Intermittent Vertical Bands

Back together and.... banding is back after 5-10 minutes. Goes away switching between sources as before.

What now - hunt for some boards or find somebody locally with an oscilloscope?

1- try make hard reset from service menu, ( not reset from user menu setting )
2-change the video output format of yours receiver.. 1080P if it was 1080i , or any other low resolution, let see at which resolution the line will not displaying.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

locate the COF in corrispondence of the fault,

Forgive my ignorance but what's a COF and how do I identify which one is responsible?

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

Factory reset from service menu done - makes no odds.

Went through every resolution available:
1080p - banding appears although interval appears longer
720p and 576p - banding visible as very feint lines - only really visible against a dark background - and disappears with cuts/scene changes. Does appear as the light/dark pair eventually though.

[Diah]

Re: Samsung UE46C800 Intermittent Vertical Bands

Factory reset from service menu done - makes no odds.

Went through every resolution available:
1080p - banding appears although interval appears longer
720p and 576p - banding visible as very feint lines - only really visible against a dark background - and disappears with cuts/scene changes. Does appear as the light/dark pair eventually though.

can you show me please

[Davi.p]

Re: Samsung UE46C800 Intermittent Vertical Bands

Cof is the chip on the flat cables between panel's board and panel you must heat under the chip, dont exagerate and heat especilly where the heat improves the picture ,yes you must do it with tv turned on.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

can you show me please

Hard to photograph but here you go.

Interstingly just watched a dvd at 1080/24p without a single incidence in over 90 minutes....

[Diah]

Re: Samsung UE46C800 Intermittent Vertical Bands

Hard to photograph but here you go.

Interstingly just watched a dvd at 1080/24p without a single incidence in over 90 minutes....

´then it sound the receiver caused this issue ... for more sure put mpeg movie 1080 on usb and play it.. if the set it owned player..

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

Don't think so. I've played material off the server using the BD straight in - still get bands.
I was interested in the fact it wasn't 50Hz.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

Cof is the chip on the flat cables between panel's board and panel you must heat under the chip, dont exagerate and heat especilly where the heat improves the picture ,yes you must do it with tv turned on.

Sounds terrifying... I'll investigate when I get some time off on Wednesday.

[Davi.p]

Re: Samsung UE46C800 Intermittent Vertical Bands

It's not terrifying, it's relatively an easy job instead, if it remains lets say a single line and it wont disappear, you can study a way to keep it pressed to bezel with shims, this is a delicate step, i was near the solution with mine, a millimeter to glory, and an incorrect shaped shim breaked in two the cof...

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

´then it sound the receiver caused this issue ... for more sure put mpeg movie 1080 on usb and play it.. if the set it owned player..

MP4 on memory stick played on native player on TV shows banding immediately.
Same File played via Bluray through receiver shows no bands for ~ 20 minutes.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

locate the COF in corrispondence of the fault, then inspect the board attached to it.

You were right on the money - small amount of oxidation on the board which cleaned off with iso - vertical bands appear to have gone although I'm now left with a single-pixel vertical red line.

Appear to have a burnt out track feeding the ribbon at D22 so scratching my head for a way to jumper that as there's nothing on the ribbon side to solder to.

As an aside do you know of any resource to find TVs with common panels? New price for mine is around 1200€ which is insane so was thinking of trying to locate a second hand one and would be easier if I could widen the net....

Panel is an LTF460HQ03 or Samsung P/No BN07-00874A

[Davi.p]

Re: Samsung UE46C800 Intermittent Vertical Bands

Buying a replacement screen in tv field is out of discussion, you can gently cut out partially the flat along the contacts to separate those two with traces corroded, bent it and solder a single filament each one with bare tin, it's non so difficult, it worths a try. For your info the corrosion is built by the screen washing with detergant..

[Diah]

Re: Samsung UE46C800 Intermittent Vertical Bands

Appear to have a burnt out track feeding the ribbon at D22 so scratching my head for a way to jumper that as there's nothing on the ribbon side to solder to

good that you still have trace of the line at the boards area so its easy to fix if you have calm hand with good light source and standing magnifier.
i face such 2 time before and i did fix it
take very thin copper wire( take it out one line from any wire) put solder on yours IRON at the top and move the cable over the solder so it will cover with solder.

solder it at the start line on the boards ( before the ribbon cable) and let it go straight over the line you want to repair. with plaster type make it fixed on the line..
now the most important take any small straight screw driver ( such for mobile ) and heat the end of it, with calm hand placed it on the cable and push down smoothly it will mild down ribbon and stick on the line.

[Anachronist]

Re: Samsung UE46C800 Intermittent Vertical Bands

Thanks gents.

I'll dig out the magnifier at the weekend and have a go. I'll let you know what transpires....