Led lights burn

[Carguy21]

Now many cars do come standard with LED tail light and now several vehicles come with LED headlights from factory, so I'm wondering if one of those OEM LEDs would ever burn and if they could, do you need to replace the whole assembly or what?

 

[Vern_in_IL]

HID's are rated 3,000 hours +

LED's are rated 10,000 hours plus.

By the time the LED's burn out, the lens would most likely be shot, all hazed and needs replaced.

There have been LED burnouts, a guy at work had a 3rd brake light, one led on the strip died.(VW Jetta)

I have also seen led burnouts on some Chrysler badged cars. It is rare but does happen, and yes you replace it as a unit. There is *no* standard when it comes to LED sockets that I am aware of?

In headlamps,
The ones I'm familiar with have a plastic plate, that houses the LED, and two small screws that hold the plate to an aluminum heat sink. I don't see why you just can't unscrew it, get an LED and some paste, and pop one back in. The only thing keeping you from doing that, is finding a LED, and being able to remove the front lens. I'm talking like vehicles like the Ford MKZ LED's. Projector LED's may never be serviceable... but Projectors should be obsolete if U.S. officials adopt new euro lights with radar sensing beam adj. tech. using multiple LED's to shape beam pattern automatically per on coming traffic.

But... the next Toyota Camry design will have a removable muti-colored lens using a gasket, perhaps to service the LED's, who knows.

 

[Jetronic]

Led headlight bulbs are replaceable. LED DRL or taillight bulbs usually not.

 

[JHZR2]

I dont know that the LED itself "burns" out the way a filament would. But the power electronics and the circuit traces sure can fail or even vaporize...

 

[Colt45ws]

They certainly can burn out if they are overdriven or overheated. Same thing really. Which is basically comes down to the design not running the LEDs too hard which generates lots of extra heat.

 

[Virtus_Probi]

Any component can fail and I have certainly blown some LEDs in the lab...typically when I run them too long without a proper heatsink and the assembly basically melts.
That said, the magnetics and power switches in the converters that drive the LEDs are more likely to fail. This is why you see strips of LEDs that are not lit in streetlights or whatever, something that was driving that string of LEDs failed or maybe the solder melted off a connection.
It's normally going to take some skill at working with circuit boards to replace LEDs or the circuits driving them, so replacing the assembly is likely to be the SOP with these lights.

 

[JHZR2]

Originally Posted By: Colt45ws
They certainly can burn out if they are overdriven or overheated. Same thing really. Which is basically comes down to the design not running the LEDs too hard which generates lots of extra heat.


What I meant was that a filament bulb "burns out" when the filament erodes and then ultimately vaporizes as one section effectively turns into a fuse.

Overdriving or overheating are not typical use conditions, but rather user/system error or failure of a related subcomponent. Different from the mechanisms of filament bulbs naturally burning out with use...

 

[ironman_gq]

They are a diode, they don't like AC which can happen when an alternator is going and they don't like over voltage. Just like a diode in an alternator they can fail without warning. More often it's the driver circuit that fails and takes out the LED in the process. Given clean consistent power LED's are very reliable.

 

[a2gtinut]

I have seen few OEM Led tail lights and all use little circuit. Good read is application notes from Lumileds.
Constant current source is a must for driving LEDs correctly.

 

[Virtus_Probi]

Originally Posted By: a2gtinut
I have seen few OEM Led tail lights and all use little circuit. Good read is application notes from Lumileds.
Constant current source is a must for driving LEDs correctly.


Yes, LED brightness is more or less directly related to the drive current and this is generally very tightly controlled in any automotive application. Any voltage based LED drive circuit is very likely to give you terrible performance.
Filament based bulbs glow because the filament is insanely hot...this is why it took Edison so long to find a suitable filament material. LEDs emit photons in a narrow wavelength range that is related to the bandgap voltage of the semiconductor material used to make the diodes, the electrons emit these photons as they cross the forward biased PN junction (typically not silicon because its indirect bandgap makes it unlikely for electron-hole recombination resulting in a photon to occur). Anyway, LEDs generate heat when in use, but they are not emitting light BECAUSE they are hot, if that makes sense.