Key Points:

  • LED strips are simple to install, however, small inconsistencies while installation may cause the LEDs to malfunction.
  • It is a very common problem for LEDs to not light up all the way. It is mostly attributes to a faulty connection.
  • It is pretty easy to fix a malfunctioning LED as long as the components are not damaged.

Often times, you may find that all of your LED strips are not lighting up. So, if you are wondering, “why are half of my led strip lights not working?”, you have come to the right place.

The reasons for a malfunctioning LED strip can be attributed to many elements. Such as faulty wiring, damaged LED, dry solder joint etc. Some of these problems are easy to fix. But sometimes, you might need to replace the LED strip completely.

In this article, I will discuss in detail, the causes of an LED strip not lighting up all the way. I will also teach you how to fix some of these problems by yourself.

why are half of my led strip lights not working

How do LED Strip Lights Work?

LED strips are made up of small LED, which are on the same or different chip. But they are all connected together and share the same power.

Fig 1- An LED Strip Schematic
Fig 1- An LED Strip Schematic

As it can be seen from the above schematic (Fig 1), a number of LEDs are soldered on a same strip, all sharing the same voltage and ground. The line in the middle indicates that they can be cut from there to create smaller strips.

If you’re wondering, why do led lights stay on when switched off, what happens is that the serial connection of the LED strip clamps the circuit even when you turn the switch off. Thus, it stays on even after being turned off.

Fig 2- LED Strip Mounting Diagram
Fig 2- LED Strip Mounting Diagram

The above diagram (Fig 2) is a general diagram for connecting LED strips. You could also connect multiple led lights to one switch if you wish to.

What Causes LED Lights to Malfunction?

There are several reasons for a malfunctioning LED strip such as faulty wiring, damaged LED, bad solder etc. So, if you are wondering, “why is only half of my led strip lights working?”, you may take a look at this chart to figure out why.

LED Strip Malfunction Causes and Solutions

Broken or fused LEDChange the broken LEDs
Overloaded power supplyStrengthen the power supply
Static electricity damageChange entire strip or a section
Too much bending of the LED stripStraighten the strip
Dry solder jointsChange or re-solder the strip section
One color of LED strip light not workingCorrect the connection between the strip and controller
Short CircuitRe-solder or split solder connections
Metal fatigue due to heatYou may need to replace the damaged section
Faulty connectionsRe-check the joints and re-solder if needed

So, your query of “why are half of my led strip lights not working?” might be due to one of these problems stated above. So, how do you fix LED lights when half out? I will discuss all of these in detail below.

How to Fix Common LED Problems?

It is completely possible to fix a lot of problems for LED strips yourself, as they are pretty simple to fix if you know basic soldering.

However, you might need to remove recessed lights from housing clips before installing new ones. Now, let’s take a look below for simple fixes of some of these problems.

Broken or Fused LED:

The LEDs are connected in series often, so when one of them is fused, they prevent the others from lighting up as well. So, in this case what you must do is remove the fused LED from the strip and replace it with a new working LED. It can be easily done with the help of a soldering iron.

Overloaded Power Supply:

Due to the overload of the power supply, all LEDs might not receive enough power to light up properly. In such a case, there are two fixes. Either increase the power of the supply, or drop unnecessary load from the line.

Static Electricity Damage:

This is one of the major cases of malfunction of an LED strip. In such a case you must remove the entire damaged section of the LED strip, and in worst case scenarios, the entire strip needs to be replaced.

Bending Excessively:

You could damage the LED strip if you bend them too much. Avoid excessive bending specially near the joints or breakpoints.

Dry Solder Joints:

Dry solder joints prevent electricity from being passed which causes the strips to not light up properly. Thus to fix this problem you may replace the section of the LED strip, or attempt to re-solder them.

Short Circuit:

Short circuits are deadly for any electrical components no matter how big or small. If the components are not damaged, you can re-solder properly and re-use the strip. But if the components are damaged, you have to replace the entire damaged section.

Metal Fatigue Due to Heat:

Another possible cause of the malfunction is insufficient heat sinking or failing to dissipate the heat generated by the LEDs. As a result, the LED strip’s weakest point will stress some cracks, causing such problems. If the copper tracks are thick enough, the problem might be solved. If they aren’t, you may have suffered damage that is difficult to repair and need to be replaced.

Faulty Connections:

In often cases, due to amateur soldering work, joints or connections are not made properly between the LED strips and the power supply. Due to which, the LEDs might not light up. It is always good practice to double check your connections and troubleshoot them properly to avoid such problems.


In this article I have answered the question of, “why are half of my led strip lights not working?” thoroughly. I have discussed the possible causes for LED strip malfunction. I have also briefed in detail about the solutions of some of these problems.

Please be cautious of electrical hazards and wear necessary safety equipment before proceeding with any electrical tasks.