Samsung LCD TV LN-T4066F Help Needed

[rleejones]

I was given an LCD TV with several problems but I thought it would be fun to try and repair it so I have gotten this far and know I am stumped. Here is what I have done so far.

1. I opened it up and inspected all of the internal components.
2. It would not power up so I inspected the power supply board and found two blown capacitors. They both measure WAY under the 1000uF they were rated for so I replaced those.
3. It was known that there were connection problems on the main board so I bought a cheap used one on EBAY and replaced it.
4. I reseated the ribbon connectors from the TCON board to the LCD display just in case before I did a test run.

It now has power, has a back light, has volume, and handles connections but it has the horizontal and vertical lines you see in the picture.

Not knowing anything about LCD displays I assumed that since there are two ribbon connectors that half of the LCD display is controlled by a set of circuits on the TCON board and the other half by the other set of circuits. So...I disconnected one ribbon connector to see if that would disable half of the LCD Display and yet the horizontal lines still continued across the entire screen.

So, I do not understand that if disconnecting one ribbon connector should have disabled half of the screen, AND if this most likely indicates a TCON board failure or an LCD display failure. How can I test both without spending money? I hope it is the TCON board since that is cheap. Thanks for the help.

[Glitcher]

Re: Samsung LCD TV LN-T4066F Help Needed

Looks like a bad panel, I had one panel that looked like the first picture. The IC on the tab bond IC severely overheating that I could smell it burning.

[tom66]

Re: Samsung LCD TV LN-T4066F Help Needed

I concur, I had the same on a 32" Samsung only a year older than this model, major difference though was I could not get any image to appear (even with lines.)

[rleejones]

Re: Samsung LCD TV LN-T4066F Help Needed

Just out of curiousity if you power up the t.v. with only one ribbon connector connected should only half the screen work or do I not understand how the system works.

[tom66]

Re: Samsung LCD TV LN-T4066F Help Needed

Yes, typically the other half will go white or black. Sometimes the halves are chained in some way and you cannot do this.

[rleejones]

Re: Samsung LCD TV LN-T4066F Help Needed

Also, would it be worth $20.00 on ebay to try the TCON board or is that throwing money to the wind in this case.

[rleejones]

I was wrong - Samsung LCD TV LN-T4066F Help Needed

I was wrong. The TV does only display half the screen when one of the ribbon connectors is disconnected. However, this is fascinating. Check out the difference in what happens when the left connector is connected versed the right disconnected.

Picture one is the left ribbon connector (when facing the TV) disconnected. Picture two is the right ribbon connector (when facing the TV disconnected.

Notice that lines only shoot across the entire screen when the left ribbon connector is disconnected. So is that more likely panel or TCON board or is that anyone's guess?