LEDs 'failing' is quite rare. There are several reasons LEDs stop working:

1. Overvoltage - LEDs will last up to 50,000 hrs, as long as they operate in their designed limits. If an LED is rated for 3.6v, it will run extremely well on 3.3v, well on 3.6v, and at 3.9v will have a much shorter life. At 5v, life drops to <12hrs if not less. Some LEDs are rated at 12v, and are exposed to 13.4-14.4v automotive voltage (when engine is charging the battery). This obviously damages the LEDs. Usually, white LEDs have a higher tolerance to overvoltage, because they are more efficient. Colorered LEDs are less efficient, meaning more heat, leading to faster decay. Many LEDs are designed for automotive use, therefore designed to cope with 13.4-14.4v. However, often an alternator on a vehicle becomes faulty and the voltage goes above this. Some LEDs are rated 10-30v, which means it is unlikely to become a victim of overvoltage. Some 24v systems however charging off solar can exceed 30v. Use caution, we cannot replace LEDs damaged by overvoltage!

2. Overheating - often caused by overvoltage, but sometimes the environment plays a part. Placing LEDs around a hot engine, or in a sauna, or other hot environment will cause a condition known as 'thermal runaway'. LEDs draw more current the higher the temperature. And the higher the current, the higher the temperature, so it is a repeating cycle to destruction. LEDs also create heat themselves, usually they can dissipate this easily. If however they are prevented from doing so, such as inadequate ventilation, insulation etc, they can go into thermal runaway.

3. Mechanical damage - LEDs are a circuit board, often a flexible one. This flexibility means less strength, so excessive bending, stretching, twisting or pressure can damage the circuit board. With flexible strip, you must never allow the strip to loop itself and must never stand on the strip. Mechanical damage symptoms include flickering, random flashing, and a tendency to change status when the circuit board is bent a certain way. warranty does not cover mechanical damage sorry.

4. Excessive vibration - being a circuit board, a large amount of vibration will loosen solder joints and cause LEDs to stop working. This can happen on off-road vehicles / trucks, but is very rare.