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In article <1149983419.671880.108230@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Uriah wrote:
>
>Thanks for the insights. I didn't realize that the glowing ends of the
>bulb, which I have seen many times, spelled failure. That will save me
>quite a bit in the coming years so I appreciate the info.
>
> Arcade games have a small fluorescent fixture in them and sometimes
>these games sit in locations for years with the bulb burned out. When
>I would go to replace the bulb the new one would just not start at all
>and then when I would try and place the same bulb in a new fixture it
>would also be dead.
Makes me think the starter is stuck shorted and the ballast is shorted.
Assuming that what you have is likewhat I had when I owned an arcade
game...
However, I would think that a fluorescent lamp burning out instantly
from this would produce some sort of flash of light at the ends.
>Can you measure the voltage on the fixture to
>check and see if it is within specs?
If you have a 2-lead ballast, voltage will not tell the whole story. To
check the condition of a ballast in a 14, 15, 20 or 22 watt 120V
fluorescent fixture with a starter and a 2-lead ballast: Rig up a 120V
40W or 60W incandescent lamp from one lead of one "lampholder" ("socket")
to one lead of the other - using the leads other than the ones going to
the starter.
If the incandescent does not glow at all, you have an open ballast or a
broken connection. If the incandescent glows at noticeably reduced
brightness, then the ballast is almost certainly good. If the
incandescent glows at full or nearly full brightness, then the ballast is
shorted.
>What would you look for? Or can
>you with the power off check the ballast with the OHM settings on a DVM
>to see if there are shorts?
Compare to a normal ballast of the same type and wattage. However, a
short across part of a winding can make a minor decrease in DC resistance
and a major decrease in impedance at 60 Hz.
> And the same with the starter, is there a
>way to check it to see if it is the culprit?
Starters should read open. But if it was used with a lamp that failed,
then it should be replaced - especially if the lamp has failed beyond
blinking or has spent a long time blinking.
>I was working on a regular fluorescent fixture that lit a display
>counter in a store . When I placed a bulb in the fixture it lit up and
>I thought it was fine but it went out within a minute and when I
>touched the bulb it was really hot. There was no starter on this
>fixture.
Most likely you used the wrong bulb for the ballast being used, such as
a regular 40 watt 4-footer with a VHO, SHO or HO ballast.
Second most likely is a failed ballast where the current limiting
element is mainly a capacitor and the capacitor shorted. I saw one of
those, but lamp life was shortened only to something like several hundred
or about a thousand hours. Or you have a separate transformer and
inductor with the inductor shorted - rare except in systems ported from
one line voltage to another.
- Don Klipstein (don@xxxxxxxxx)
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