Long story short, got some used fixtures(4 ft) and bulbs and installed them in my garage. Some of the bulbs were orange in color and didn't match the rest of the cool whites. Bought a box of 4ft. F40 T12 cool whites to replace the orangey F40 T12 SP35 bulbs, the new bulbs wouldn't work, I used some of the new bulbs on other fixtures that were not from the used fixtures I got and they worked fine. Moved some other cool white bulbs from another used fixture to the fixture that wouldn't work and they worked fine. So, fixture seems fine, the bulbs are the problem. There were 6 bulbs left in the box and none of them work in the used fixture. What gives, I thought T12 was T12, am I missing something with bulb specs? I know there are holes in the story, I'll fill in the blanks as needed.
New T12's won't work
- Thread starter drew67
- Start date
nissan_crawler
Well-known member
I don't know the answer, but I had this exact problem. Old lights burned out, new ones wouldn't work. Three different fixtures, same result. The last remaining bulb would work anywhere, but there was only one spot in one light that a new bulb would work.
I tossed them and put t8's in, so I'm not much help. The only thing I could pull out of my **** is that maybe the ballasts were weak, and the older bulbs required less current, but I have no clue.
I tossed them and put t8's in, so I'm not much help. The only thing I could pull out of my **** is that maybe the ballasts were weak, and the older bulbs required less current, but I have no clue.
I thought of that so I bought a pair of 34w bulbs and they still didn't work.
You bought a box of bulbs, some worked some didn't? Could you get bulbs to light up in any fixture but those that didn't work wouldn't work in any fixture? I'd say bad bulbs? It happens, in fact I see it quite often, what manufacturer?
Aceman
Well-known member
Do your new lamps have green tips?
I've had issues with those, the brand I was using was Sylvania I believe. The last time it happened I was replacing bad ballasts and lamps in a dental office. I ended up swapping around lamps to get the green tip lamps to work, most of the time I ended up with one old lamp and a green tip in the same fixture. 2 green tips on one ballast=didn't work.
For the record, I've never had issues with the green tipped T8's, only the T12's.
I've had issues with those, the brand I was using was Sylvania I believe. The last time it happened I was replacing bad ballasts and lamps in a dental office. I ended up swapping around lamps to get the green tip lamps to work, most of the time I ended up with one old lamp and a green tip in the same fixture. 2 green tips on one ballast=didn't work.
For the record, I've never had issues with the green tipped T8's, only the T12's.
nadogail
Well-known member
I have been told, and accept as probably true, the hardest job for a fluorescent ballast to do is to start a cold new lamp. In an effort to avoid replacing ballasts, I will admit to have swapped in warm new lamps from another fixture; I left the building on time with all the lights working.
nate379
Banned
I've killed a few balasts by putting in a new bulb while the lights were on too. Did it to 3 housings in my old shop till I figured something was going on (yeah I was a little slow on that one)
Phillips, they're lower mercury than any other bulb
Bingo
I think this may be the problem, I was installing the bulbs with the lights on, but I think it was affecting the bulbs and not the ballast. I took my last six bulbs and put them in my hanging shop light with the power off to see which ones worked, two were bad, I then took two good bulbs and installed them with the lights out, hit the switch, lights on. Those two new bulbs do start a few seconds later than the rest though. I'm buying another box of Sylvania's to finish the rest of the lights. Thanks for the replies, I'll post back if this doesn't work...
