Q: Hi, my Samsung 75" LCD TV has just this week started having a dark horizontal section on the screen. It looks like the backlight is dimmer in a horizontal line directly in the middle of the screen. I was wondering if this is something you would be able to fix? The actual image is still perfectly clear, it's just much darker in the very middle of the display now. I have pictures I can share as well.
A: What is described is a common problem for a back-lit LED LCD TV (as opposed to edge-lit LED LCD TV) where one of the LED strips has failed resulting in less light along the length of the strip.
Here is a picture illustrating how the TV panel looks when the top layers are removed (the LCD panel and the light diffuser sheets):
The horizontal strips with bright spots are 6 different LED strips and the lights are the individual LEDs on every strip.
The number of strips, the number of LEDs on the strops, the physical and electrical specifications of the strips vary greatly from model to model, from year to year, from size to size and , simply put, there is a huge diversity of strips out there.
Since LEDs on the strip are connected in series when one fails the whole strip fails.
In most TVs the strips themselves are also connected in series - one, two or more series resulting in one, two or more circuits that require power.
And again, when a single LED fails and burns open, much like with Christmas lights, the whole circuit fails.
When a single LED fails it can also short (instead of blowing open like a fuse) and usually if that happens the strip and the TV would continue working without that single light. It would manifest as a darker area on the screen, but if all others work fine it will be hard to spot.
For various reasons most TVs out will have the whole screen dark if a single strip fails; there are some, however, that will not and yours is among them - one strip has failed, but the others still do work.
So what should be done when a LED TV back light LED strip fails and what would it cost?
It would apparently need to be replaced. Repair is an option and in the early days of LED TVs technicians were trying to repair strips, but they quickly learned several important things:
The effort and risk and cost to take apart and then assemble the LCD panel are so much higher than the individual LED strip price - and the factor increases drastically with the size of the panel - that it is practically not worth replacing / repairing individual LEDs on the strop.
Just as important, if not even more important, LEDs in a panel can be compared to a set of tires on a car.: they start working together and they wear out together.
When one of your car tires busts from being too worn out you are practically guaranteed that you have 3 more waiting to do just the same in the very near future.
Notice we are not talking about accidents here, just regular wearing resulting in a failure.
So just like individual LEDs are not worth repairing/replacing it is actually logical that the same applies to the whole strip: if one strip gets replaced there are 5 or 6 or whatever other number of strips that have been working for so many hours and are worn out and ready to fail.
So after a few years of repeat failures and upset customers it has finally dawned on most TV repairmen that
TV LED strips must always be replaced in a package
You may suspect this is just another fairy tale to suck money out of customers, but it isn't. It is really the repairmen that are left holding the bag when they replace a single LED or a single strip and have an upset customer return within a week or a month claiming that "your repair failed" when the repair would turn out to be holding just fine, but another LED from the assembly has failed.
So what does it cost to replace LED strips in a TV?
The question does not have a very simple answer as there are several factors that vary greatly from TV to TV and they have large impact on price.
Simply put the cost of replacement is that of a set of brand new replacement LEDs plus the cost of labor to take apart the LCD assembly, replace the strips and assemble the panel back.
Like car technicians TV repairmen rely on bulk importers for the parts and so you can shop around to see what the cost of LED replacement strips is for your particular TV make and model.
There is less of a difference here between OEM and aftermarket parts since they all come from China, the de-factor world supplier for anything LED.
What is really crucial is that the strips are new and that the vendor is reliable enough where if problems occur they wouldn't play chicken and would just send replacements - it's usually cheaper for them to do than than to engage in shipping back and forth.
There are a number of reliable vendors in USA in this regard. ShopJimmy.com is an example and there is a number of good names on eBay as well, but especially on eBay you should beware - there is plenty of bad offerings there as well.
ShopJimmy is a good reference for cost of the LEDs.
Then comes the labor.
The size of the TV is the first factor here as it affects both the time it takes to do the job, the room required, the labor involved (anything over 65'' better involve two people when moving around the LCD!) and the risk of breaking the LCD panel - something few shops will discuss upfront.
Oh, then the brand and the model. Some cheap brands like TCL (and maybe some not so cheap, things can always change) sometimes tend to glue the LCD panel to the other layers making it practically impossible to detach and rendering the whole repair procedure useless.
Sony, on the other hand, does not usually do such bad tricks, but their panels [used to] have so many individual parts and screws it takes literally twice as long to do a Sony panel compared to say Samsung or LG.
Because of all that there is no simple and elegant way to put general function for the cost of the labor.
It is usually a function of the most that the repair shop can consider the buyer can afford that will still make sense for the vendor to do.
This may sound bad, but ever failing TV prices in shop make it actually a fair deal for the customer. Nobody would paid $500 for repair when they can buy a new TV for $400. They wouldn't even pay $300, right?
So much so that LED replacement for smaller size TVs, while relatively cheap and affordable has been rendered useless compared to the price of a new TV from the store.
Congratulations OEMs, this is something they've been trying to achieve for a long time!
It does make sense to replace LED strips on relatively large (50'' and above), high-end and, naturally, expensive TVs. 50'' Emerson or TCL , for example, are still better off replaced with a new TV.
50'' Sony that used to cost twice the TCL may still be worth having repaired.
Number-wise you will find out that LED replacement labor may vary anywhere between $50 and $300 depending on the model, the repairman, the client. We for one would not do any LED replacement for less than $80 labor and that would be for particular 47'' and 50'' commercial models.
Last word: in any LED replacement project there is always the risk that once assembled, the LCD would have an issue - usually a crack or a missing line or whatever it is that affects and is not repairable.
If the screen was dark to begin with then it may have been there prior to the start and neither the technician nor you will ever know.
In case of the described situation where screen is visible and quality is good then it will be known that it was shop that broke it while working on it.
No shop would normally - and in our opinion should ever - give warranty against such a possibility.
But once the LED strips are in they can't be taken out and returned to the store: once because of the labor to take them out (which is notable0 and second because many times they are glued and taking them out will render them impossible to use afterwards.
So we, for example, do LED replacements in two separate parts: customer pays for a set of brand new LEDs and that portion of the payment is something they will never get back , regardless of the outcome.
Then if we deliver properly functioning TV we get paid for the labor.
If there is a problem then we lose the labor payment, but the customer still loses the cost of the LED strips.
It does sound better to buy a new TV, doesn't?
I told you!
Good job, manufacturers...you found the sweet spot...something that fails often and is too costly to replace.
Welcome to the world of disposable TVs!
