20 Most Recent Samsung LN46B640 LCD TV Questions & Answers

The problem is a defective LCD panel.

T'Con board fault. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/ Faults & possible causes to LCD screen are given with illustrations.

sounds like you need to replace your main pcb

You will most likely need to have the set diagnosed. Vertical lines can be the result of a defective t-con board, faulty lcd panel/t-con connections, or a faulty panel itself. Do the lines stay or do they come and go? Older Samsung sets are known for faulty LCD panels!

There are so many reasons for this fault. If you wish to get more details, check this link. http://electronicshelponline.blogspot.com/ Selecting the view option, either to Mosaic / Time slide, can be selected by the drop-down list, at the top left of the display window, will make surf easy. You can also do a search, by type in the brand name/model number/IC used, in the search box at the top right of the display window. Details of faults with illustration are given.

It sounds that a loose contact to its flat wire connection that goes to panel from T'Con board. Re-seat it once and check. If you wish to get more, check this link. It has screen-shots to faulty LCD TVs, and you can compere to your TVs present appearance. http://electronicshelponline.blogspot.com/ Pull up previous posts, either by type in the Brand name to your set in its search box, or view it in Mosaic / Timeslide / Flipcard option. Select view option by the drop-down view box, at the top left or the display window.

The machine is still under warranty from samsung so I would call 1-800-samsung to find the nearest service center. Problem could be caused by a bad main board, bad lvds cable or a defective t/con board or lcd panel.

Contact TV-Parts dot com, the have t6he board you need.

Tom Miller
Broadcast Engineer

Power supply module will be the first place to look.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:

Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide

http://s807.photobucket.com/home/budm/allalbums

http://en.wikipedia.org/wiki/Capacitor_plague

Try unplugging any devices near the TV one by one and see if that helps.
I had the same problem with my picture shaking on all HD channels and found that it was my land line phone interfering with the signal.
Hope that helps!

if this tv is under warranty i would call samsung, there could be three board that could be going out on it one is the techon board, main board, but you also my need the ip board changed out to. i repair samsung all day long and i see this problem a bit.

Yes,Samsung is Korea,Sony is Japanese.Read both manuals carefully,goes to there websites for idea or back where u buy it for more imfo.

The problem is the LCD panel went bad, it can't be repaired, you have to replace it.