SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

[Bxscig]

I have a SAMSUNG LN46A550P3FXZA that just started with this weird issue of like extra snow like distortion. I am not sure if it the main board, cable, LCD or what not.

Does anyone know what it may be from these pictures? It happens across all inputs. When I took it apart to get part numbers, I powered it on with the back off for the heck of it and it worked for about 2 hours and was still good. I shut it off, put he back on and then the issue was there as soon as I turned it on. Sometimes it takes about 5 to 10 mins for the issue to appear when the TV is started but sometimes it is instant.

Here are some pictures

http://www.nyblacktl.com/samsung/IMG_2010_resize.jpg
http://www.nyblacktl.com/samsung/IMG_2012_resize.jpg
http://www.nyblacktl.com/samsung/IMG_2013_resize.jpg
http://www.nyblacktl.com/samsung/IMG_2014_resize.jpg
http://www.nyblacktl.com/samsung/IMG_2015_resize.jpg
http://www.nyblacktl.com/samsung/IMG_2045_resize.jpg

I have been having a hard time trying to find another main board to see if that is the issue as it was with another Samsung TV I have - LNT-4665F... 2 for 2 have issues within 2 years... just my luck. Any help would be appreciated.

[Bxscig]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I don't have the pictures of the parts where the white/bright parts just look WAY TOO bright.

[tom66]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Try this.

TV power off (in standby.)

On remote: Info Menu Mute Power (TV should power on with service menu)

-OR-

If this does not work, turn it off again, then try on the remote Mute 1 8 2 Power... some models use that code instead.

When in the service menu, select "Reset" or "Factory Reset".

[Bxscig]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Try this.

TV power off (in standby.)

On remote: Info Menu Mute Power (TV should power on with service menu)

-OR-

If this does not work, turn it off again, then try on the remote Mute 1 8 2 Power... some models use that code instead.

When in the service menu, select "Reset" or "Factory Reset".

Thanks I will give that a shot. Does that just reset the video settings back to default?

The discoloration as well as the location of it changes... sometimes its blue, sometimes its reddish or its the white but I will give it a shot.

Hope to report back soon!

[tom66]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Thanks I will give that a shot. Does that just reset the video settings back to default?

The discoloration as well as the location of it changes... sometimes its blue, sometimes its reddish or its the white but I will give it a shot.

Hope to report back soon!

Yes, it resets everything. The TV will power on again as if it is new from the retail box. So if you have any important calibration or particular picture settings, back those up.

One thing I forgot to mention was that you must press the buttons in sequence, not all together at once.

I have seen this before on a Sharp LCD TV, but it only affected green. Just needed a reset.

It could also be incorrect panel config -- especially if it occurred suddenly -- or T-con motion-processor fault. (The 100/120 Hz frame doubler this TV uses has lots of overheating problems causing odd artefacts.)

I have the LE40A656, very similar TV, I have fixed two of them. The T-con board failed on one (green lines -- but fixed in location), bad capacitors on the other. I kept the second one, but I found the motion enhancement to be very annoying, so quickly turned it off.

[randtek]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I would try cleaning the connectors of the LVDS cable. They can cause some weird symptoms. I do this by disconnecting the connectors, cleaning the contacts by burnishing with a pencil eraser, then cleaning with an electronic contact cleaner such as "Blue Shower". I have fixed a lot of picture issues with this technique.

[tw2005]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

There's some data in these, may or may not assist.

PDF was simply was too big.

looks like there's service menu (what TOM has mentioned)

Plus a HIDDEN Service menu. Looks like there's some onboard test patterns there as well.

How to enter the hidden factory mode.
a. into the factory mode
b. key input : 0 + 2 + 1 + 4 + exit
c. select option byte menu -> in menu -> out menu
(... hidden menu appear...)
** hidden menu : Video/Scaler, Enhancement, SOUND, Dynamic Contrast, LNA+
- FBE3(image enhance IC) generate internal pattern


Samsung_LN32A550P3F_LN37A550P3F_LN40A550P3F_LN46A550P3F_LN52A550P3F_ch_GPR3X_4X_5X

[tom66]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Wait a minute... there's a hidden menu inside the hidden menu?

[tw2005]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Or is it a hidden menu, in a hidden menu which is hidden? LOL

[hijodalgo]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

that's T-Con board problem..

[tom66]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Whilst it does look like a T-con board problem, it was a config problem on the Sharp LCD I fixed.

[T-Rex]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Hi, I have what I think may be a similar problem but factory reset and reseating cables on tcon did not fix it. I will create a new thread with pictures.

[suzannetodd1]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I saw a post on here that someone bought a repair kit for T-con (as I am having the same prob with my TV). My question is how easy is it to repair a T-con or do I need to take it to professional????

[tom66]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Have you ever done any surface mount soldering? In particular a 48 pin chip with leads 0.8mm apart?
If so you can do it - if not you should ask a professional.

[onrushmatt]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I have the same tv (Samsung LN46A550P3FXZA) and I am trying to figure out if my T-con board needs to be replaced, or just some caps.

I have light experience in working with circuit boards but feel confident in some basic soldering. I have attached a picture of the service menu, which I heard may be a way to fix the issue with the picture. My options are 'Option Byte' 'White Balance' 'B/B Movie' EPA Standard' 'Sound' 'Hotel Option' 'EDID' 'CHECKSUM' 'View Log' 'Front Data Viewer'. I assume the options between will be available once clicked into a menu.

I also attached a photo of the picture issue as well. I think it is the same as the OP's.

I would really appreciate any information or tips, and hope this old thread can bring me some answers.

Also threw in a photo of the model on the side of the console.

[budm]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Bad GAMMA Voltage ref. IC, Look for AS15 IC on the T-CON board.

[Kallla]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I have some similar (or not?) symptoms on my home TV a Samsung LN32B650T1FXZA ... attached a picture of how image look (image remain with high luminosity regardless of input source used).

Any taught, help or information to speed-up debugging is highly appreciated !

[budm]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

Look at the T-CON board to see if it has GAMMA IC AS15, or AS19, very likely to be your problem.

[Fix4Fun]

Re: SAMSUNG LN46A550 P3FXZA - Weird Contrast & Discoloration issue

I had this exact model of TV: LN46A550P3FXZA with the exact same problem, weird colors on the screen: sometimes white where black should be and red spots pixels, pixelating, depending on the input used. It was the T-con board (not the motherboard despite the differences in the inputs). When I got a brand new T-con board (model #: V520H1-C06) from eBay for $32, and swapped out the old one, all my problems went away! I hope this helps someone else considering replacing their T-Con board!