A good looking solar light can be a great add to your home's backyard or yard. They work for quite a while before they, like all electronic devices, break down. Here's a few tips to making them work again.
The solution to any problem lies in its assessment. That is exactly what we need to do in this case too. To know what's wrong with your solar yard light, you need to know what makes a solar light.
The casing on the outside protects the equipment on the inside. The glass on top is designed to let in all the sunlight for the photovoltaic cell to soak it in and for the LED to glow effectively in the dark. The photovoltaic cells may be inside the glass or on top of the case, depending on what model you choose.
The LED is under the glass case, inside a cylindrical glass designed to refract the light as brightly in all directions. It is connected to the batteries and the light sensor.
The batteries in a solar light are generally single AA NiCad batteries. They are rechargeable and pretty good for jobs like these.
The sensor is nothing but a simple photoresistor that cuts a circuit as long as sunlight falls on it. When it gets dark, the sensor stops and the circuit between the battery and the LED is complete, lighting it up.
Everything is mounted underneath the top cover as a single unit.
Diagnosing the Problem
Now that we know what's in a solar light, we can get to fixing it. There are two types of solar lights, and both have the same answers to their problems. There are some visual results that you can use to know exactly what's wrong with the light, things like:
The light is placed in a spot where there isn't enough sunlight. This will happen after changes in the seasons as the earth revolves.
The light turning ON after a few hours of sunlight, during the day. This means that the sensor doesn't work properly and the light basically runs out of battery after, like an hour into the evening. This means your need to fix/replace the sensor, depending on how bad a state it's in.
If the light is not ON during the day and still doesn't come on in the night, there can be a problem with the sensor, the battery or the LED itself.
If the light flickers, there's a problem with the wires or the LED.
Fixing the Solar Light
Dismantling and Cleaning
Probably the simplest thing to do that might solve your problem. It can sometimes happen that dust and dirt will settle on top of the LED, dimming it, or on the sensor, making it malfunction. Another problem with the sensor is that if the transparent coating on it is not top grade, it will slowly turn opaque due to direct exposure to sunlight.
Based on the model, there will be screws on the top or bottom of the case. Unscrew all that you find and leave them such that you know which one goes where.
Inside the case will be the entire electronic arrangement. The batteries will probably have a casing for themselves that you will need to unscrew.
Remove the glass casing on top and clean it with a cleaning fluid or a damp cloth. If there's a lot of dirt on the inside, you can rinse it under a sink.
Take out the battery from the battery case and clean out the case and battery. Take out any dirt or bugs that are settled on the contacts that might disconnect the battery. If the light is old, you can sandpaper the contacts a little to remove the stubborn rust and chemical deposit.
Battery Problems
The easiest problem to fix. Clean the battery contacts and replace the battery in its casing.
If the problem was the dirt, the light should be working fine now.
If not, check the wires connecting the things together. If it's loose somewhere, get it fixed back on from someone who can solder the wire back on. If there are small screws connecting the wires to the electronics, there may be a chance that the wire came out of the screw. Fit it back again and put the battery back in.
If your light was old, chances are the battery is dead. If you have spare battery, use that to see if the light comes on in the dark. You can also use the battery off another solar light, or you can get new batteries.
If none of this works, the problem then lies in either the sensor or the LED.
Sensor and LED Problems
The problem here is you won't really know for sure which one is really to blame. You may replace the sensor only to realize the LEDs blown, or the other way round. There is one fix that you can do with the sensor that may help you decide.
One reason for the sensor to not work is because there is dirt on it. Clean it up and see if it works. If there is no dirt, then check the coating on the sensor. Most solar lights come cheap and are made of cheap stuff. What happens is that the thin coating of plastic meant for protecting the sensor, actually shuts it down. This can happen because the coating turns opaque after months of exposure to sunlight. What you can do here is chip it off, replace it with clear plastic wrap or scotch tape.
If the light is still not back on yet, this means the sensor is dead. Again you can't really know whether it's the sensor or the LED, so you either replace the sensor or the LED. I would go with the sensor first. If replacing the sensor doesn't work, the LED is dead and you will have to replace it.
The thing with solar lights is, most of them are made cheap and sold cheap, even if it's in an attractive case. But the essence of buying a solar light is to reduce one's carbon footprint, so it would be good to fix the problem rather than buy a new light.