Fluorescent lights won't come on

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  #1  
Old 01-30-20, 07:22 PM
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Fluorescent lights won't come on

I have two florescent light fixtures, one in each closet. They are both single tube fixtures using F40T12 tubes.

This is the first time using these fixtures since moving into this house. Both fixtures have the same exact behavior. Won't turn on. I removed the tubes and they look burnt, dark gray color near the ends of the tubes. I saw some tubes in the garage (presumed new since they don't look used or discolored at all) and put them in.

The new tubes won't come on either. But when switched on, both ends showed a faint orange glow.

I tried to tap it a little, nothing. But when I put my palm on the tubes, it lit up fine. Turned switch off, back on, does not come on. Put my hand on the tube and wiggle a little, it came back on. Once on, trying to tap or wiggle the tubes will NOT cause it to flicker off.

I left it on for an hour. Then I turned the switch off and on, and it works fine. But if I leave if off for say 30 minutes, turning the switch back on will not do anything. The only way to turn it on is to touch the tube with my hand.

Any idea what may be wrong? Should I get new tubes, new ballast?
 
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Old 01-30-20, 07:43 PM
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Are they properly grounded? Some fixtures need the metal case to grounded to induce the bulbs to fire.
 
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Old 01-31-20, 03:25 AM
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Since the ends are dark it indicates that they had been working in the past so my guess is that it is a ballast problem. Would not hurt to check that they are getting 120 volts.

I would replace them with LED's and get rid of the ballasts.
I prefer the ones that have Neutral at on end and power at the other.
 
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Old 01-31-20, 05:14 AM
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I cant give any professional advice, but in my experience.... that's just a typical issue with florescent lights. What I'm saying is, its not uncommon.
I have a small one above the kitchen window & one in my current shop that does the same thing. My choices in my opinion is to replace them or tap/bump them around until they come one.

I have found over time that you can turn the bulbs a little back & forth in some case & kinda-sorta fix it sometimes. I guess the little connectors on the end of the bulb &/or the connectors on the fixture get dirty, greasy, corroded, etc & loose good contact, hence the reason to have to bump it or turn the bulb just a bit.
If you don't want to do this, my opinion, is to replace them with some different type LED fixtures.

Just my two cents.
 
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Old 01-31-20, 05:49 AM
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I would nix the fluorescent lights and switch to LED. You could install new ballasts but they would cost about as much as switching to LED and you still might need new bulbs. You can either replace the entire fixture or you can buy LED replacement bulbs. If getting the replacement bulbs I would get the line powered (ones powered by 120 VAC) and disconnect your fixture's old ballast.
 
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Old 02-02-20, 10:53 PM
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well, it's never as easy as I think LOL.

I was going to just go with a new fixture instead of wasting time trouble shooting whether it's the tubes or the starter or the ballast, but then the fluorescent tube fixtures are mounted on the closet wall. The closet walls are fully lined with cedar planks. Whoever installed the fixtures had precut the cedar planks to fit around the fixtures, or more then likely the fixtures were already there when someone lined the closet with cedar so it cut around it. So if I remove the fixtures I will be left with rectangular hollowed out footprints that new fixtures cannot match.

I think I will have to somehow retrofit what I have existing. If I remove the ballast I guess I can use LED tubes and keep the existing fixture box?
 
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Old 02-03-20, 05:33 AM
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Yes, replacement LED bulbs are easy to find. That's a very common replacement. Just make sure you order line powered bulbs which will allow you to remove or bypass the fixture's ballast. Then follow the wiring instructions that come with your bulb. Some bulbs you connect hot and neutral at the same end of the fixture while others you connect hot to either pin on one end and neutral to either pin on the opposite end. You might need a couple wire nuts for making the wiring change inside the fixture but it's pretty quick and easy.
 
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