Samsung LE40M86BDX strange colours.

[Dang]

Hi, quite certain this issue is a bad T-con although I've recently tried a replacement and exactly the same issue showed it's self, that card went back as faulty so my question is: could it be something else like the main board, the panel it's self maybe? I've tried various in the service menu but nothing really effects it, thanks, Andy.

[tom66]

Re: Samsung LE40M86BDX strange colours.

Doesn't look like t-con, looks like LVDS setting is wrong to me. Check service menu panel option.
From standby Info Menu Mute Power then check menus for Panel Option.

[Dang]

Re: Samsung LE40M86BDX strange colours.

Hi Tom, I've tried but nothing works, I'll try again.

[tom66]

Re: Samsung LE40M86BDX strange colours.

check JEIDA or VESA, for LVDS mode?

[Dang]

Re: Samsung LE40M86BDX strange colours.

OK, what part of the service menu do I need to look in, I can't find anything relating to the above?

[tom66]

Re: Samsung LE40M86BDX strange colours.

Can you post a picture of the options available, and also what panel is installed in this TV?

[Dang]

Re: Samsung LE40M86BDX strange colours.

This is what I see, I've played with the Panel type and vendor settings but it doesn't do much really, can brighten, change the colour of the writing, seems to invert the noise I see from the background(blue sparkles) to a similar distortion in the writing. Any ideas where the LVDS settings are in the menu, seen JEIDA before somewhere but can't find it??

Panel number on the side is AC08, I hope that helps.

[Dang]

Re: Samsung LE40M86BDX strange colours.

So I've measured all 22 test points on the T-con card, they re as follows:

1)15.03v
2)14.77v
3)14.63v
4)12.44v
5)11.61v
6)10.64v
7)9.96v
8)9.63v
9)8.27v
10)8.11v
11)7.67v
12)6.89v
13)6.49v
14)6.35v
15)5.13v
16)4.84v
17)4.22v
18)3.35v
19)2.60v
20)0.62v
21)0.51v
22)0.29v

Vcom2 measured at 6.50.

Not too sure what all this means but from what I've read before, it's probably within specification, any ideas Tom?

[tom66]

Re: Samsung LE40M86BDX strange colours.

Looks fine to me.

[Dang]

Re: Samsung LE40M86BDX strange colours.

That's good, so what do you think may be causing the issue I see, main board possibly, service menu settings, driver board on panel?

[tom66]

Re: Samsung LE40M86BDX strange colours.

It's 90% main board, IMHO.
You might have cold solder BGA fault (common issue on these) on the main board, or a corrupted EEPROM.

[Dang]

Re: Samsung LE40M86BDX strange colours.

Hi, so I've now replaced the main board but I have exactly the same issue, on the original I did notice a small SMD capacitor had blown, I've now replaced this but it's still the same, so I took the shielding off and couldn't see anything else wrong, so back in the Tv and now with a spare board. Has anyone else got any other ideas as to what might be wrong with this? I would hazzard a guess at it being the screen but I would of thought it would be one side or the other as it has two separate drive boards. One symptom that may give a clue is a constant fast oscillation of the back light, like a strobing effect and this is dependent on menu settings, could the power supply be a cause maybe?? any help will be greatly appreciated as usual, thanks, Andy.

[Dang]

Re: Samsung LE40M86BDX strange colours.

Please any ideas on this? I would really like to try all I can before giving up on it, thanks.

[Dang]

Re: Samsung LE40M86BDX strange colours.

Another thing I should add, if I disconnect the T-con card the strobe effect goes, why I don't know, it's a mystery to me????

[truep]

Re: Samsung LE40M86BDX strange colours.

I had one similar to that that the previous owner had replaced the main board with the wrong one. I was able to fiix it by adjusting the the LVDS setting to the correct panel size.

[Dang]

Re: Samsung LE40M86BDX strange colours.

OK and thanks, how does the LVDS setting look in the service menu? I've tried everything I know and looked specifically for it but I can't find it, any ideas? This is an 86 according to the back of the Tv yet it's had a board change in the past, one from an 87 and the eprom had been changed in the past along with the usual caps in the PSU.

I would also say it's possible as you describe as the replacement board was exactly the same in all numbers bar the tuner.

[mmartell]

Re: Samsung LE40M86BDX strange colours.

Lools like a form of interference. Bad lvds cable ?

[Dang]

Re: Samsung LE40M86BDX strange colours.

So I have just sold the M86 after learning that AUO screens require a main board programmed for them, this was taken from a donor Tv with the screen suffering from some dark patches, the Tv in question here had a board for an M87 although they too can use AUO screens(donor Tv), so my question is this, I'm left with two main boards for Samsung screens, is there a way to reset them so they work with AUO LCD screens and AUO T-con boards? both boards I have just show a series of coloured lines on the vertical.

[Dang]

Re: Samsung LE40M86BDX strange colours.

Any ideas please?

[Dang]

Re: Samsung LE40M86BDX strange colours.

So any ideas on how to make this compatible? everything was working just fine before the board swap, could shorting pins 5 and 6 on the Eprom help?