Problem with store sign florescent Lighting - Electrical issue?

Question

The sign has 6 florescent Lights. 3 on 1 side and 3 on the other each tubs about 7 ft long.
The 3 on the left side work and the 3 on the right do not
There is only 1 ballast and wires come out of 1 side and feed the left that work and wires come out of the right and that side does not although the top right bulb has a slight glow.
If you feel the ballast it feels hot and checking the outside temp of it is about 156 deg..
Can the 1 ballast go partly bad?
What should the voltage be coming out of the ballast. The input is 120V
I have replaced the bulbs so I guess that I am stuck at this point?

Thanks
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Answer 1

The ballast is bad. The bulbs work on a high frequency and high voltage The voltage could be depending on the unit from 200 to 400 volts AC the frequency is much higher than the 60 cycles input. if you have 120 VAC in and new bulbs the only thing left is the ballast.

Answer 2

A couple of tips:

Ballasts do run hot in normal operation. Ballasts do provide more than line voltage especially for large commercial fluorescents.

Have you checked the sockets to make sure that the fluorescent tubes are firmly seated in them? Since the tubes and the input voltage are OK then check the sockets (which tend to arc and burn if the tubes are not tight) to make sure before replacing the expensive balalst.they

Answer 3

first you have too check the wires that go from those lights that are on and see if they are firmly attach into the sockets on the ones aren't coming on some times a lose lead makes the light glitter a bit like you describe it so check them out