I need light fixture repair help.

[TonyInVa]

Hello. I have an old Reef Breader light fixture. Half the lights are not lit. In the past when this would happen, I would just find the bulb that appeared burnt and replace. I have done that but still half are not lit. I ensure the negative was to negative and positive give to positive.  I believe it is a good solder. I dont think it is the ballast but not sure. How would I go about testing things with a multimeter?

[paul b]

I don't know what a Reef Breeder light fixture is but if we are talking about an LED fixture, take a short piece of insulated wire and strip the ends.  Short out the terminals on that "bulb" LED.

It is low voltage so you won't kill yourself but use insulated wire anyway because the voltages vary in that fixture depending on where you are touching.

 

If the rest of the lights work.  Replace that LED or maybe you have it backwards.  You may have another LED burnt out so I would short out each one until you get the thing working.

LEDs either short out or have an open circuit but the jumper will tell you what light it is. 

 

I build my own fixtures and have to do that all the time.  You may have more than one that is bad.

If you short it out and some lights come on, that one that you shorted is also bad.

[TonyInVa]

2 hours ago, paul b said:

I don't know what a Reef Breeder light fixture is but if we are talking about an LED fixture, take a short piece of insulated wire and strip the ends.  Short out the terminals on that "bulb" LED.

It is low voltage so you won't kill yourself but use insulated wire anyway because the voltages vary in that fixture depending on where you are touching.

 

If the rest of the lights work.  Replace that LED or maybe you have it backwards.  You may have another LED burnt out so I would short out each one until you get the thing working.

LEDs either short out or have an open circuit but the jumper will tell you what light it is. 

 

I build my own fixtures and have to do that all the time.  You may have more than one that is bad.

If you short it out and some lights come on, that one that you shorted is also bad.

Hello Paul. Sorry for not clarifying, but it is an led light fixture.  If I am understanding you correctly, I would just bridge the positive and negative on the solder points where the bulb touches the board. I would do this with a piece of insulated wire. Here is a picture of the type of led used.

[paul b]

Yes that is correct.  Those LEDs work on 3 volts and are wired in series.  Different color LEDs have different resistances so there may be 12, 16 or a different number of them on a circuit.  That doesn't matter.  To find a bad one, jump it out like you said.  If that LED is the only bad one, the rest will light.

 

If you have 2 or more bad ones, (not likely) you would have to jump all of the bad ones out at the same time. 

They go bad all the time and if you need to replace one, you should "glue" it to the aluminum heat sink using Thermal adhesive, available on Amazon.  Regular glue is not good because the thing needs to transfer the heat from the LED to the aluminum heat sink or the LED may have a short life. 

 

If you get the fixture working with the jumper, you can just solder in that jumper and leave it like that until you get the thermal adhesive.  I have those jumpers all over my lights for years.  

Of course it is better to replace the LED but if you want to leave in the jumper, just turn down the brightness of the fixture a little because by installing a jumper you are forcing "slightly" more voltage through each LED potentially reducing their life.  But turning it down slightly will correct that. 

 

(Master Electrician 50 years)