Troubleshooting a fluorescent light fixture

[TriumphFan]

Four bulb fluorescent fixture with an electronic ballast and replacement LED bulbs. I have 12 of these fixtures and this the only one that is sporadic. Sometimes it lights and sometimes it doesn't. If I go in and twist one of the bulbs I can usually get it to light-up. I don't want to throw parts at it so should I replace the tombstones or the ballast?

 

[walta]

My gut says the problem is in the LED tube but it is just a guess.

Have you moved the LEDs to another fixture?

It seems likely if the problem was a loose connection in or near the tombstone you would have identified the problem by now so the next thing I would do is swap the ballast with one in another fixture and see if the problem moves with the ballast.

If the problem does not move with the other parts you have nothing left but the
tombstones and wires.


Walta

 

[The Cobbler]

ballast is my guess, that's why I would never buy ballast rated LEDs. ( more parts to go bad)

 

[Sumboodie]

Remove the ballast.

 

[cybrdyke]

You know a few things for sure.
The tube lights, so you know it works and the ballast works.
The first step is to verify that the tube is listed as being compatible with the ballast model you have. Not all electronic ballasts are exactly the same and they dont all work with every LED tube. The tube manufacturer has the burden of testing their product with common ballasts.
Second step is to ensure that all connections at the socket are correct and tight.
Third step is to make sure that the brass in the sockets isn't overly corroded or dirty.
Fourth step is to make sure that the ballast is mounted tightly in the fixture. Typically, it's grounded via one of the mounting screws and if they are loose, you can lose your ground.
Finally, a very old ballast can lose some performance from the capacitor inside and will need to be replaced. Normally when this happens, the tube will be obviously dim.
Good luck,
CD

 

[TriumphFan]

Thanks Everyone. I have 12 of these fixtures which are about the same age and using the same bulbs and ballasts. The other 11 are working perfectly.
I am going to replace the ballast with an extra one I have and go from there.
I'll report back.

 

[Innovate1]

As others have mentioned this is why I use ballast bypass LEDs. Don't have to worry about noise from the ballast or it going bad.

But since you already have the bulbs you plan of replacing the ballast seems like a good one.

 

[TriumphFan]

Thanks Innovate1. Funny but it's been working fine these past two days without me touching it. Weird.

 

[Sevenhills1952]

psychokinetic interference

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[Innovate1]

Remove the ballast.

If the bulbs aren't ballast bypass bulbs you can't just get rid of the ballast. Not sure but some bulbs may be rated for use with ballast or bypassed.

 

[cybrdyke]

Funny but it's been working fine these past two days without me touching it. Weird.

And so, like I said, your ballast is good and your tubes are good. You've got a connection issue. It's either the ballast case, which is grounded to the fixture by a screw in the foot of the ballast. If this is loose, your ground is loose and the fixture operates intermittently. Or it's a wire connection at the socket that's either loose or corroded. Both are simple fixes.
People always blame ballasts. In cases like yours, a ballast doesn't die and then come back to life. It's just a dumb transformer. It either works or it doesn't. So, if it's strong enough to fire the tubes, it works.
CD

 

[walta]

And so, like I said, your ballast is good and your tubes are good.
CD

One day ago TriumphFan says he plan on installing a different used ballast but today he says it has not acted up for 2 days implying he has done nothing in the last 2 days. God only knows if the random used ballast that has been getting kicked around the shop for a few years is still undamaged if it was even operational a when it was put in storage so long ago. So on what bases can you say the Ballast or its replacement is defiantly good?


In no post does TriumphFan say he moved say he swapped the LED into one of the working fixture and He says they are “the same age” implying they are a few years old. So on what bases can you say the LED tube is defiantly good?

Walta

 

[Sevenhills1952]

You're in kings row having identical working lights. So simply switching part by part is the key, of course making sure connections are good with intermittent one.

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[cybrdyke]

One day ago TriumphFan says he plan on installing a different used ballast but today he says it has not acted up for 2 days implying he has done nothing in the last 2 days. God only knows if the random used ballast that has been getting kicked around the shop for a few years is still undamaged if it was even operational a when it was put in storage so long ago. So on what bases can you say the Ballast or its replacement is defiantly good?
An electronic ballast will not operate intermittently. If it has power, it will either work or it wont. Even if it's very old and the capacitor is diminished, it will still fire the tube, but possibly to a dimmer level. OP reported intermittent operation. That's not the ballast.

In no post does TriumphFan say he moved say he swapped the LED into one of the working fixture and He says they are “the same age” implying they are a few years old. So on what bases can you say the LED tube is defiantly good? Because it fires fully and stays stable. If it were a failed lamp, it would misbehave by blinking, strobing, being dim, or just not firing. There's a driver in that tube that works very much like a ballast. It will either work or not. Since it's firing the tube, it's working.



Walta

Is there something in the OP's description that indicates that the ballast is bad? He even says that if he fiddles with the lamp it will come on. How do people translate that to a ballast issue?
CD

 

[TriumphFan]

One day ago TriumphFan says he plan on installing a different used ballast but today he says it has not acted up for 2 days implying he has done nothing in the last 2 days. God only knows if the random used ballast that has been getting kicked around the shop for a few years is still undamaged if it was even operational a when it was put in storage so long ago. So on what bases can you say the Ballast or its replacement is defiantly good?


In no post does TriumphFan say he moved say he swapped the LED into one of the working fixture and He says they are “the same age” implying they are a few years old. So on what bases can you say the LED tube is defiantly good?

Walta

I have a brand new ballast I ordered by accident last year that has never been installed. It has not been "kicked around the shop."

I have not swapped the LED tubes from one fixture to another to see if the problem follows the tubes. Perhaps I should.

The fixture has been working normally for the last three days or so without me doing anything to it so it is an intermittent problem.
Appreciate the help Everyone.

 

[walta]

CD I use to say “that can’t happen with electronic after getting egg on my face a time or two I now say “I have not see that before” It has been my experience that things electronic can and will fail in every way imaginable and most problem start intermittently and get worse over time.

Last month I repaired an LED tube that worked intermittently. Everything in the tube was a close fit to save room after they wave solder the circuit board they ground off all the leads that protruded above the surface. This made for some bad solder connections that worked sometimes and not others. Yes it is rare but it did happen once and it will happen again in some other way. The one thing I am sure of is given enough time everything breaks even rocks.

I did not say what part I thought was at fault. I suggested the OP switch known good parts for suspected parts starting with the easiest parts to move.

Walta