Samsung forum: Horizontal Lines on Samsung LN-T4661F 46" LCD TV

Thanks.

Hi - Sorry, I have not resolved this yet. I checked the power supply, and all the capacitors look normal. I have no power on/off symptoms, just the lines.
I've removed and reseated all cable connections with no affect. I replaced my T-CON card - no change. I recently discovered that if I very gently twist the LCD panel, the lines will come and go...so I'm afraid it might be the LCD panel itself. I'll post if I learn anything else.

Hey Cavette--

You and I share the exact same problem - I have opened up the back many times to look for bulging capacitors and have found none. Twisting the tv works for me, but unless I hold the tv in the exact right spot, it will revert back to having 3 horizontal lines until it gets past the normal "warmup" phase. I'm willing to play with the tv more, but I wish I had more concrete of an answer i.e. yes, replace the T CON board or yes, replace the LVDS cable.

Anyways, how is your tv doing? Same issues? Any updates/recommendations to share with those of us having similar problems? Thanks

My thread: http://forums.cnet.com/5208-13973_102-0.html?messageID=3283242

e-mail me if you want! t.ryanbrooks@gmail.com

Hi
My problem ended up being a bad TAB bond to the LCD panel itself. See the last photo at:

http://home.myfairpoint.net/~langhoff/PhotoAlbums/album_1271775431/

The problem area is in the red circle. TAB = Tape Automated Bond. The 4661 LCD panel has a couple dozen TAB connections, each with numerous parallel connections. Each TAB connector is just a thin ribbon, and touching the bad one with a non-conducting probe (a chop stick in this case) caused the lines and shadowing to go nuts. Touching the other TAB connections had no affect.

Taking apart your TV is dangerous, and powering it up while it is apart is more dangerous, so I'm not recommending you try this. I did not try this until the TV became unwatchable and I had resigned myself to buying a new one. With the arrival of fall and cold mornings, the lines had become large black areas that would linger through an entire show sometimes.

First, I removed the TV back, then the base (including the plate it attaches to), speakers, plastic bezel & power switch, and side panel jacks (screws only; I left the electrical connection). This leaves the LCD itself. To get at the TAB bonds, I removed the metal frame around the LCD panel. Once the metal frame is off, there is not much structure, nor anything holding the LCD to the backing other than the TAB bonds themselves. I then propped the LCD against a wooden speaker on a wooden floor. I removed the power switch from the bezel and reconneted it to the main board so I could turn the TV on. I also reconnected the speakers just in case the audio output requires a load.

After confirming which TAB bond was bad, I applied a piece of non-conductive foam wrapped in electrical tape over the area circled in red. It was just thick enough to compress the tab bond when the metal frame was re-installed. The picture has been perfect since. Good luck.

Thanks so much for this post Cavette. I'm really excited to have the issue identified now. I've thought this was the issue for a few weeks, and I tried to get everything stripped from the tv that I could, but I still wasn't able to get the metal frame off of the LCD. I must be missing a screw somewhere, but I probably wasn't being as thorough as I needed. There were a lot of electrical components (power board and inverter) that I wasn't sure if I needed to remove or not.

Are you guys using any kind of manual guide, or just going with what makes sense when you are stripping the tv? I must get that metal frame off.

Thanks again, Cavette.

You're welcome. I have no manual, but was motivated by a youtube video of a guy who fixed a TAB problem on a Sony by adding material under the frame.

On the 4661F, the metal plate/subframe that the base connects to, and the jacks on the left side of the TV (if I remember right), have screws that pass through the LCD frame that need to be removed. To get at the screws that secure the jacks you have to remove the plastic bezel first. Also, the metal LCD frame uses #1 philips secured with lock-tite that are easy to strip, and it's also easy to miss one screw. None of the major circuit boards on the 4661F need to be disturbed except for the jacks on the left side of the TV.

Agree that this 'fix' is a band-aid. All local repair resources reported that bad TAB = bad panel and ~$1000 to replace (there are better TVs available now for less). If you know of a place that rebonds for a reasonable fee please share. Glad to hear you found your problem (and that I'm not the only one)

Cavette, thanks a lot for the tip!

I took apart my Samsung (lnt4661fx/xac) 46" LCD TV as per your suggestions, applied the TAB bandaid and seems to be working fine so far. The problem used to happen all the time before, and it's been running fine all afternoon since the repair (I powered it on and off many times). Fingers crossed from here

Interestingly, I was unable to locate the "broken" TAB bond. When I took the TV apart and plugged it in while apart to test, it worked all the time. It's as though having it all apart healed the problem. Touching the tabs made no difference, there was no distortion regardless of what I did. Regardless, I applied the suggested padding on a couple of bonds on the side where the problem happened all the time in the past.

I took some pictures along the way and posted here:

http://picasaweb.google.com/DrDjurovic/SamsungLnt4661fxLCDProblem?authkey=Gv1sRgCNSP_4XU-cb69gE&feat=directlink

Hope it helps those brave enough to try this. I'm not an expert myself but I'd say you need to be very careful, there are a couple tricky spots but all in all it's fairly easily doable.

Here are a couple notes:

1) First put the TV screen side down on a flat soft surface and take off the back plastic cover
2) Now take off the speakers, metal plates, side panel and support bars to free up the front plastic panel and the LCD panel with the metal frame. I've highlighted their placement in the picture. I didn't have to take off anything else. I disconnected the front panel power-on and speaker cables because this makes it easier to handle the parts. I did not disconnect the main power supply cable as I didn't want to take off the big metal case around the power supply board. But I was careful to keep the associated plate tucked in safely so it didn't get damaged or loose to damage other parts.
3) This enables you to lift up the main body of the TV (LCD+frame+electronics) and leaves only the plastic front cover with power-on cable attached.
4) Now you need to take off the metal frame from the LCD panel so you can access the bonds. The trick here is that the screws for the frame are on the front side of the TV (while so far you've been working with the front side down). I carefully lifted the TV upright so I could access the front side and unscrew.

5) Once you unscrew the metal frame from the front, the frame easily comes off. You need to be very careful here as the LCD panel is only attached to the main body of the TV via the TAB bonds (exactly dozen in my case) on the upper side of the TV. There are some bonds on the left and right side, but those are more like wings, not really attached. So if you remove the frame and the TV is not standing upright (or lying back, with the panel side up), you risk tearing the TABs off. I would not recommend taking the frame off with the TV lying on the panel side down position (which is how you start taking it apart).

6) Once you take the metal frame off, you can access the bonds so you need to do some testing with the TV powered on in the "broken-apart" state. You need to get the plastic frame (that you took of earlier) close enough to the panel so you can hook the power-on cable back, plug in the speakers just in case, and turn on the TV. See if you can locate the broken TAB by touching them with some soft non-conductive material (remember, the TV is ON powered by high voltage and these can get VERY hot so use caution here !!!).

7) When you locate the broken TAB, apply some padding on it's position on the metal frame so when you put the frame back it presses against the bond and keeps it in place. I used my son's spongeball (hope he forgives me when he finds out .

8) Now put the metal frame back and retest to make sure it still works. You probably want to wait for some time before testing to allow the TV to cool down. Even with the original problem before the fix, once my TV warms up and the problem goes away, if I turn it off and back on quickly, the problem doesn't happen. It only happens once the TV cools down.

That's all the advice I could give. If you have questions, feel free to post here. I have more pictures to share if you need more details.

Also: if someone finds a proper fix (a way to replace or resolder the TABs) please post here.

I have the same problem you had with my 52" version of the same series set. I was wondering if you felt the problem was caused on part by the fact that it was not wall mounted and created some sort of torque on the swivel stand? It seems that twisting the set on the stand corrects the issue, but only temporarily. This would be my second major repair needed for this set, the first being a new power supply due to busted caps, but Samsung actually covered that repair for me through a local authorized repair shop free of charge. I am not optimistic they will do the same for this issue. Before I proceed, I wanted to get you feedback on how you had the TV set up, either on the wall on using the swivel stand. Thanks.

If anyone else reading his wants to answer as well, feel free. Thanks.

Thanks for the reply. So why wouldn't the repair just be new tab bonds? Why a new lCD panel or all new unit?

I am minutes away from call Samsung to see what I can make happen. I am hoping that since they repaired the power supply on 12/17/09 that they might have a heart an repair this too. A 27 month old TV should not have such major repairs when they should last 10 years. I think these are both manufacturing defects but no way would Samsung admit it. I am hoping that they might make repairs on a case by case basis. Will keep you posted. Thanks.

Next time it's gonna be a Sony....

Mechanical stress could be a factor. Obviously, once wall mounted, the TV is going to see less mechanical stress. Our TV is on the stand and we often swiveled it relative to the base, which I avoid doing now. Several other posters have reported failing bonds near the corner of the screen. This makes sense; if you deform a square or rectangular frame, the maxmimum stress is at the corners. You don't see airplanes with square windows anymore! (google de Havilland Comet if you like engineering trivia). Anyway, I've also read that the TAB process is not very robust and manufactures are now moving to better methods. You should not have to treat these TVs with kid gloves.

Email me directly (bsdjuro at yahoo.com) for more pictures. But there isn't really much there once you get down to the metal frame. There are screws all around it, on the front side of the panel in my case.

BTW, since the last updated I posted here "by drdjuro - December 12, 2010 7:02 PM PST" and my reworked fix (replaced the sponge pads with solid rubber), my TV has been working flawlessly!

Hi - I'm glad to hear you got them to do the right thing. I tried your approach on several calls, but their responses were consistent:

Will you pay for the repair? -NO
Can you provide the part and I will pay the labor - NO
Can you provide a discount or voucher for a new TV? - NO

The people I talked to were professional but appeared to be following a procedure or script. They listened, but were probably coached not to give up anything that would cost Samsung any money. From what I've read, Sony customers with similar problems were treated much better. My next TV will be a Japanese brand.

Just got off the phone with Samsung and after pleading my case:
less than 3 yr old TV
Black lines across top
Local technician concludes ribbon/microchip failure - needs new lcd panel - too costly to fix

THEY ARE NOT WILLING TO HELP AT ALL. I am writing a letter to Office of President Samsung. I am not giving up yet on $2,000 expenditure for TV that lasted less than 3 years. Any other advice on how you got yours fixed or would you let me reference your service requet # or location?

How do we all get together and get some help on this!!!