I have a fixture in my kitchen that has (4) 40W bulbs. Last week the outer bulbs grew dim and finally the fixture quit lighting up at all. I replaced the bulbs today...and the outer bulbs are not working. I've tried replacing all 4 bulbs, still the outers aren't work (even put a known good bulb in each of the outer locations). Is this the sign of a bad ballast or another issue? All connections are nice and tight.
Think they are paired two inside two outside. Ballast may be gone. Open the cover in the middle and you'll see them. Tony
Most likely the ballast. Maybe a bad socket, but that's a stretch.
A decent ballast for two 40W bulbs should cost less than $20, even if bought at an Ace Hardware store.
You might also look for specials on dual 40W hanging fixtures which sometimes sell for less than $15. Take it apart, toss out the sheetmetal and get a ballast plus two bulbs and four spare sockets for that price.
Jeff
I agree.
It is most likely the ballast.
PJ South Jersey
Better yet buy it, take the parts, sell it at a garage sale for 20.00. :D Maybe 30.00 on ebay.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ A high humidity location..
Make sure power is off and then clean the fixture. Clean exposed parts except for the interior portion of the bulb sockets. Clean the old fluorescent bulbs and let them dry. Put old bulbs back in. There is a good chance that it will work again. Note: Over time, a thin film of grime accumulates on all exposed surfaces and its conductivity varies by humidity. The grime provides alternate electrical paths and essentially shorts out the fluorescent fixture to the point where it fails to light.
The more conductive the grime(higher humidity) == less chance the bulbs will light up.
You're a moron.. I've rejuvenated several fluorescent fixtures just by cleaning them.
I am wary of the ballasts in cheap fixtures sold in hardware stores and home centers, and even a few not-really-cheap fixtures. There is such a piece of garbage as what is often called a "residential grade" ballast. You can get as little as half the normal light output from the bulbs with these, and I suspect also sometimes reduced bulb life. If the ballast comes from a fixture with chains, it may overheat in a fixture mounted flush against a ceiling or a beam.
If the ballast is bad, I would replace it with a decent one. I think ballasts sold separately at hardware stores and home centers are still good.
- Don Klipstein ( snipped-for-privacy@misty.com)
I know this is sometimes true. A film of conductive grime on the bulbs can afect the electric field distribution within ones that are trying to start. So can lack of grounding. Bulbs sometimes fail to start if the fixture is not grounded.
But also check for any of the other usual suspects - bad ballast, bad or corroded socket, whatever.
- Don Klipstein ( snipped-for-privacy@misty.com,
Your "Note" at the end of your post is BULLSHIT! If that were the case, every automotive repair shop in the country would be operating in the dark. The grime on the flourescent tubes is so thick, even the light can't get through, BUT THEY STILL LIGHT.
1) The grime does NOT conduct. 2) It's conductivity does NOT vary with humidity. 3) The grime does NOT provide "...an alternate electrical path..."Stick to what you know.
And another thing...how did you find out I'm a moron? Who squealed?
This might be a good time to upgrade to the new electronic ballast that use T8 lamps. I don't have the numbers with me, but T8 lamps with the electronic ballast produce more light and consume less energy than the T12 you probably have right now.
--Mike
Good points Don, especially the overheating one. I'm sort of glad I put that after my "suggestion".
I was once shocked, just shocked, to find a cheap flourescent fixture with no inductive ballast at all, It used just a series capacitor. Yes, just a capacitor. No, it wasn't an "electronic ballast", 'cause it was at least 20 years ago.
Jeff
Also the cold starting feature of the new ballasts is really important in a garage. I switched over and never looked back.
Dave
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.