Samsung LE32B450 display problem

[artois7]

Hi all,

Just purchased this TV. The display is very distorted with 2/3 vertical strips running down the tv. The blacks all appear yellow, and when you leave the TV running, the whole screen turns into a yellow wavey madness.

I've taken a few pictures which I hope show up the problem, but the cameras died now so I couldn't take as many pictures as I wanted to!

I took the back off and unplugged the mainboard, which resulted in just the backlight and a black screen, so from this I think? the panel is OK. Same result by unplugging (what I believe to be) the T-con.

There's a very loud buzzing coming from the power supply, which stops if you unplug the mainboard.

Sound works fine.

I'm thinking it's either the T-con or the mainboard. The T-con is available used on ebay for as little as £5, but the mainboards are more £30-£35 or so.

Can anyone point out where the T-con is?

I hope the images are OK. I haven't got my proper camera right now, so I'm using an old one. Picture 6 is what happens everytime you switch channel.

[drpj23]

Re: Samsung LE32B450 display problem

It looks like your TCON is integrated into your panel.

But, judging by your last pic, the text seems unaffected by the distortion which can lead to be the main. And it seems your OSD is affected but only the background of the text (ie text box/menu) but the text itself seems fine.

Btw, disconnecting the main to test panel functionality is a poor test since doing that practically means the panel is "OFF".

[artois7]

Re: Samsung LE32B450 display problem

I don't think it is integrated;

http://www.ebay.co.uk/itm/Samsung-32...item2327c88689

The text is unaffected, but the vertical strips does affect the colouring of the menu.

Ok, fair enough, I just figured since it lit up without any yellowness or obvious damage without the main plugged in, that it would be ok. Have you got any thoughts on the buzzing power supply?

[tom66]

Re: Samsung LE32B450 display problem

Try on a dark image -- see yellowness? Then repeat main unplugged.
Panel has the T-con on board on this model, not user serviceable.

[drpj23]

Re: Samsung LE32B450 display problem

I realize that this model will bring up TCONs for sale but with that said, this model is usually made with a samsung panel while yours is a chi mei.

The buzzing is probably the transformer(s) and that is normal. I know on some samsungs unplugging the main enables the backlights (it is a test procedure) but I cannot remember if it activates the rails to the main. If you have a multimeter, you could confirm this and make sure voltages are in specified values.

But I would put some money on the main (some but not all).

[artois7]

Re: Samsung LE32B450 display problem

Try on a dark image -- see yellowness? Then repeat main unplugged.
Panel has the T-con on board on this model, not user serviceable.

Yes - on a DVD I had playing, the blacks showed up almost entirely yellow. Could you clarify on 'repeat main unplugged'?

I realize that this model will bring up TCONs for sale but with that said, this model is usually made with a samsung panel while yours is a chi mei.

The buzzing is probably the transformer(s) and that is normal. I know on some samsungs unplugging the main enables the backlights (it is a test procedure) but I cannot remember if it activates the rails to the main. If you have a multimeter, you could confirm this and make sure voltages are in specified values.

But I would put some money on the main (some but not all).

Ah right, ok. I thought the board might be hiding under the metal chassis. The buzzing is really quite loud; you can hear it from the other side of the room over the sound from the TV. On this model, when you have the main unplugged, simply inserting the power cord lights up the screen. You don't have to turn the set on. Having the main plugged in with the T con unplugged results in having to turn the set on to activate the screen.

My multimeter isn't here currently, but I will get it back soon. I actually work at a TV service centre so I'm hoping there's a main board in stock there.

[tom66]

Re: Samsung LE32B450 display problem

I mean, repeat with the main board disconnected from the LVDS but the TV normally powered up. To me it looks more like panel rather than main board...

[artois7]

Re: Samsung LE32B450 display problem

I mean, repeat with the main board disconnected from the LVDS but the TV normally powered up. To me it looks more like panel rather than main board...

Yes, that results in a black lit up screen without any yellowness.

[tom66]

Re: Samsung LE32B450 display problem

And with a black source, you get the yellow bars? Hmm...

[artois7]

Re: Samsung LE32B450 display problem

Not bars as such. The yellowing is more of an overall thing. The vertical bars on the screen are more of a discolouration depending on the background image, rather than one solid colour.

I read about a Samsung test earlier within service mode, but I couldn't find the option it was referring to.

The previous owner told me it happened by itself, rather than accidental damage to the screen.

[drpj23]

Re: Samsung LE32B450 display problem

The only reason I insisted main was since the text seemed unaffected which is unusual.

But, from the pic with the warning text, you can see a bordering affect which is usually caused by a failing TCON/panel so ya maybe I will agree...

[tom66]

Re: Samsung LE32B450 display problem

Most panels have a limit to their white level which is usually set to the maximum pixel value (255) or just below it. Even a glitch can let through more light than the panel is designed to.

[artois7]

Re: Samsung LE32B450 display problem

I found a board at work today that is faulty and was removed but kept in storage. The board's fault suggested poor quality picture, discolour and a vertical stripe down the screen.

I've now swapped the boards, as I figured it would at least change the problem. I still have the vertical blocks/sections in the same places, but all the colours have changed. Black screens are now purple on the dvd player, or a grey with a border effect. The TV generally seems a bit more healthy, but still definitely faulty.

I'm starting to think both the main board AND the panel are gone.

[woodware]

Re: Samsung LE32B450 display problem

Hi, I saw similar problem on my lcd TV. The flex connectors on the top of the panel-T-con,someone disconected earlier. But, when turned back, few of the metal connectors were distorted. When I made straight and carefully connected in T-con, the stripes were gone.

[netdent]

Re: Samsung LE32B450 display problem

I have one of these with a cracked panel, boards look same as yours, only problem is it has a blink code! Not sure if that's down to the panel being smashed or if it had a fault prior to the damage? Would be willing to sell the boards

Ronnie

[tom66]

Re: Samsung LE32B450 display problem

Samsung do not use blink codes. The LED will often continue blinking for some time after power up.

[netdent]

Re: Samsung LE32B450 display problem

Samsung do not use blink codes. The LED will often continue blinking for some time after power up.

Ok, switches on but red led continues to blink, don't remember if it went green first lol, looked at too many tv's since

[tom66]

Re: Samsung LE32B450 display problem

Usually goes off eventually. Though I do have a 40" Sammy LCD right now -- the LED blinks continuously if the T-con is unplugged (but TV otherwise works, i.e. sound and source selection.)

[netdent]

Re: Samsung LE32B450 display problem

Will give it a try Tom, but it showed no backlight while blinking, would be handy to know boards are good, no t con on this panel

Ronnie

[tom66]

Re: Samsung LE32B450 display problem

Unplug main board to power board connector to test backlight of TV. It should light up.