LED exterior lights attract errors

LED lamp defective: what could be the cause? These are the causes

The current LED lighting is very durable, but sometimes an LED lamp breaks. This can happen after a short time or even after several years. I am often asked by readers for advice as to why their LED bulbs or the entire luminaire have failed. In this article I summarize the most common causes of defective LED lamps.

Table of Contents

LED lights do not work

Current LED lamps and lights are very durable and usually last between 15,000 and 50,000 hours. Nevertheless, LED lamps can also break. For one thing, that can on the lamp itself lie. Due to the relatively complex structure of an LED lamp, there are many sources of error. The LED itself rarely burns out. Defects occur much more frequently in the ballast or LED driver.

According to my own observations and the letters of many readers, a certain trend can be identified. Then go No-name LED lamps more often suddenly broken after a short time than the lamps from brand manufacturers. One reason for this could be that the unknown manufacturers from the Far East install cheaper components and do without certain tests for lighting duration and switching resistance.

The error does not necessarily have to come from the LED lamp itself. Are very common external interference the cause. These include:

  • Power fluctuations
  • Incorrect electrical installation
  • Incompatible dimmer
  • Unsuitable transformer for low-voltage lamps

Frequent LED defects

Every now and then I get questions from readers about why their LED light sources have broken in this or that situation. Of course I can't see clairvoyantly and judge every mistake from a distance. However, some errors occurred frequently, which are now described in more detail in the following sections. This allows you to analyze your own LED defects more precisely and find out what the error is.

LED lamps defective after a short time

Your LED lamps keep breaking? Do you change them and after a short time are they defective again? You should first check whether your LED lamps break due to an external influence or burn out for no reason. In the second case, you should see whether you have relied on cheap no-name lamps so far. Then it is advisable to replace it with a branded LED lamp.

LED ceiling light does not work

Your LED ceiling light lights up no more? You should first check that the fuse for this circuit has not just blown. If the ceiling light has already worked, the light source may have broken. Then you should check whether the bulbs are replaceable. In this case you can replace the light source with a new LED lamp with a matching socket.

It can also happen that a newly installed LED ceiling light does not work. In this case you should check the wiring again and make sure that the light is connected correctly. If the ceiling light still remains dark, it is usually due to the following external circumstances.

LED lights go on and off

Your LED lamps always go on and off? If the lamp has worked properly so far, it is now probably broken and needs to be replaced. If the error occurs with the newly installed LED lighting, the cause is usually due to one of the following conditions.

Fixed LED defective

In many modern lights, the LED light sources are permanently installed. These cannot be changed by the user himself. In luminaires with a large number of integrated light-emitting diodes, a single defective LED is usually less bad and is hardly noticeable. In the case of luminaires with only a few or even just a single LED, a defect poses a greater challenge.

LED strip no longer works

If your LED strip no longer works, it is rarely the LED strip itself. LED strips have a large number of LEDs, all of which are on most strips parallel are switched. Even if individual light-emitting diodes fail here, this is hardly noticeable because most of the LEDs continue to light up. Most LED strips have a controller with a remote control. This is usually the cause of a defect.

A broken LED strip usually no longer lights up at all. On the one hand, this may be due to the cabling. You should check the connection from the controller to the LED strip. It is especially important to check the connector between the cable and the LED strip, because this connector is very sensitive. There must be a solid electrical connection to the contact surfaces of the strip.

If no error can be seen here, the cause is most likely with the LED Stripe Controller. Most controllers are supplied via a plug-in power supply. To rule out a defect in the power supply unit, you may be able to use another power supply unit with the same voltage (usually 12V) for testing. If the LED strip still remains dark, the controller is probably broken.

  • Individual LEDs stay dark? - No problem due to parallel connection
  • LED strip stays dark? - Check the connection between the controller and the stripe
  • Power supply defective? - Use a different power supply unit with the same voltage for testing
  • Controller defective? - Repair not possible for users / not worthwhile from a cost perspective
  • Here you can find new LED strips and controllers


Above, the most common errors and defects in connection with current LED lighting were considered. In the following you will find further information on how to find the exact cause of the error patterns mentioned.

Checklist for external malfunctions

Operation on the dimmer?

After converting old light sources to LEDs, problems often arise with old dimmers. If you want to operate your LEDs on a dimmer, both the dimmer and the LEDs must be marked as dimmable.

Operation on the transformer?

After converting old light sources to LEDs, problems often arise with old halogen transformers. You should use a suitable LED transformer for trouble-free operation.

Operation on the motion detector?

After converting old light sources to LEDs, problems often arise with electronic motion detectors. You should use a suitable motion detector for trouble-free operation.

Electrical installation checklist

There is a risk of death from electric shock when working on the electrical installation. Troubleshooting and modifications may only be carried out by professionally trained persons. Otherwise you should hire a qualified electrician for your own safety.

Try the lamp somewhere else

If your LED light source does not work properly, you can take it out of the lamp and try it in another lamp with the same socket. In the best case scenario, this lamp should be connected to a different circuit. If the light source is working properly here, you have already limited the error to the original location and can further isolate it there.

Permanently installed lights can also be connected to a different circuit in the event of problems. Here, of course, the effort involved in disconnecting and connecting is greater.

Power fluctuations

Power fluctuations can be caused by large electrical consumers such as boilers or fan heaters. When these consumers are switched on, there are strong voltage fluctuations, which means that the light in the apartment flickers for a short time or certain devices even switch off for a short time. Current fluctuations can occur in old or incorrectly dimensioned electrical installations.

On the other hand, electricity fluctuations can be caused by large industrial consumers in the vicinity. If you find strong voltage fluctuations as the cause of your LED defects, you should definitely consult an electrician or the energy supplier.


There are many reasons for defective LED lights and broken LED lamps. This article gives you a good overview of common LED problems. The tips mentioned will help you to isolate the errors and, ideally, to correct them.