Yes, one CCFL lamp out will cause the TV to stop working!!! And it is VERY easy to fix yourself for only $20 - no more difficult that removing and installing components from a PC and changing a lightbulb!
Our LN-T4066Fstopped working a few months ago, and was out of warranty. I had a Samsung field tech come out to the house to look at it. He tried to replace the power supply board, and that did nothing to fix it. He then told me that it was most likely the Inverter PCB or the entire Panel, but that he didn't bring an inverter with him (even though my service request to Samsung had identified this as a potential problem). At the end of the day, he charged me $90 for "diagnosis", which essentially told me that me TV didn't work (well I kind of knew that already), and that I would need to either replace the inverter for $55 plus $150 labor, or replace the entire panel (essentially the entire TV minus the case, the power supply, the inverter and input panel) for $515 plus $150 labor!!! Since the TV only cost $1,050 to begin with, this seemed like a stupid option. I called Samsung's customer service to complain, but they were worthless and told me that since I didn't purchase an extended warranty, that I was out of luck and there was nothing they could do for me.
So, by taking his suggestion about a bad inverter panel, I opted to replace it myself (very simple - just have to unplug the TV, open up the case [bunch of screws on the back] - the inverter panel is on the left side of the back of the panel - unplug two cables, undo 3 screws and pull out the board - insert the new one in the opposite order). I found a brand-new replacement inverter online for about $20 from Tri State Module (
http://www.tristatemodule.com/casearch.aspx?SearchTerm=BN81-01801A+&asug=&view=grid&lang=en). After replacing it, I found that recommended solution didn't work (backlight would still flicker for a second and then go out), so I figured there had to be something wrong with the lamps themselves.
Since the panel itself wasn't working, I figured the TV was a lost-cause (even though it was only 2 years young), and figured that I could try to rip the panel open and see if there were any shorts inside the light panel that could easily be identified. The opening up of the panel took me about 30-45 minutes. Requires to remove the frame that mounts the PCBs, and then to remove a bunch of screws around the metal bezel of the LCD screen. After the metal frame is removed, there is a plastic frame holding the LCD screen and the backlight assembly. This is held together with a series of plastic clips and some rubber grommets. Be careful when taking this all apart, because there are some flexible PCBs between the processor and the LCD panel with fragile connectors that must be removed somewhat gently.
Once you take the frame apart and remove the LCD panel, you will see the inside of the backlight with an array of 16 CCFL light bulbs. At this point, I re-connected the power supply and inveter and input control PCBs to the backlight, and plugged it in and turned it on. (Be very careful when powering up a disassembled TV, as there are some high voltage components inside). When I fired up the TV with the backlights exposed, I could clearly see that one of them was out (they would all turn on for a second or two and then go back out). I couldn't believe that a burned out lightbulb could take down an expensive TV like this.
I seached on-line for replacement bulbs, but couldn't find much information on what ones I needed. I ended up coming across a website for CCFL bulb replacements, and they gave instructions for how to measure for a replacement. I measured and ordered a 950mm x 3mm replacement bulb (
http://www.ccflwarehouse.com/30x90fuspcc.html) for about $20 plus shipping. It wasn't an exact fit, and I think a 4mm diameter bulb would have fit better. I installed the new bulb (it's literally as easy as changing a light bulb - but be careful because their thin and fragile and I think they contain mercury like most fluorescents). After taking out the suspect bulb and putting in the new one, I fired up the TV again. This time the backlight lit up and stayed lit!!! The $20 light bulb fixed my problem that a repair tech told me would cost over $700 - what a waste!
After the light bulb has been changed, the TV just needs to be re-assembled in the reverse order that it was taken apart (make sure you keep all of those screws in ziplock bags so that they don't get lost when you're taking it apart, and your life will be easier when you go to reassemble).
This is a relatively easy fix for anyone that has ever repaired a computer, or done any other sort of minor electronics repair. I am by no means a TV repairman, but this was so simple. I can't believe Samsung's design is soooo poor that it can't disable an inverter channel when it detects a burned out bulb, so that the TV could still function for many years (albeit a tiny bit dimmer). They should be ashamed of themselves and their greed of wanting to sell you an entire panel or new TV, when something as simple as a burned out light bulb that costs $20 has gone bad.
Please re-post this solution everywhere you can find a forum about this issue!!! These lighbulb changes should keep your TV running for quite a long time - better yet, buy an LED back-lit TV if you're in the market, these CCFL bulb designs are bad (or, at least Samsung's is).
