In my office, I have four fluorescent T-8 4'/4 lamp surface mount fixtures. All four are on the same three-way switch. I just replaced 3 of the four fixtures. Two of the new fixtures adjacent to each other (same location opposite sides of the high part of the ceiling) do not work. The other two that work are on opposite sides of the office over both exterior doors. I used a non-contact tester and both non-working lights have a hot wire. Since the other two fixtures work, does this mean I have two separate neutrals? Any ideas on troubleshooting would be greatly appreciated.

  • To be clear you replaced the entire fixture not just bulbs? – Kris Jun 11 '15 at 22:25
  • Yes. I completely replaced three of the four fixtures. The three used the T12 lamps and were old. The new ones use the T8 lamp. – Greg Jun 11 '15 at 23:53
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    Recheck taps. Possible wire slipped out of connection. – Kris Jun 12 '15 at 2:12

Try removing the tubes that are not working and carefully replacing them to ensure good contact. On some fixtures neither tube will light up if one tube in not getting good contact.

  • These are new fixtures with new lamps. Each can light independently of the others. There is one of the three new fixtures that works. This seems to be something with wiring in the circuit. Probably going to have to climb into the attic. – Greg Jun 12 '15 at 19:01

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