Sorry Jazz but... Your test didn't prove much about the status of the fixture, beyond that it was hooked to power and the internal wires were not burned open.

Again, it is NOT a transformer per se as in the sense of isolation transformer, step up or step down transformer, it is a ballast transformer or just ballast.

Recall the "job" of the ballast resistor in ignition systems back in the 60's? This is similar.... but different. (High power to start then reduced power to run.)

The lamp is a gaseous discharge design. It requires a high voltage to ionize the gas to initiate current flow through it. The ballast provides that. Once the "arc is struck", so to speak, the ballast must limit the current flow to prevent the lamp from self destructing. The ballast acts as a "choke coil" where its X sub L (inductive reactance) is an AC resistance that limits the current flow through the lamp. In fact a resistor could be used for the ballast action but would dissipate much more power.

Power in Watts in an AC circuit depends on resistance as well as reactance (Impedance.)

In an AC circuit the power is computed by multiplying the current (Amps) times the Volts and then times the cosine of the phase angle. If the voltage and current do not peak together during an alternation of the AC current then less power is produced. The inductance of the ballast shifts the phase of the current vs voltage so the power is reduced and the lamp doesn't act like a flash bulb.

Electric type folk use the mnemonic device "ELI the ICE man." where E is voltage, L is inductance, and C is capacitance. This is to remember that in an inductor (L) the voltage leads the current and in a capacitor (C) the current Leads the voltage.

(This material may be included on the mid term exam.)

If all this just sounds like a new age version of Jaberwocky then put away your VOM and follow my previoius post's instructions or just go buy a fixture.

Pat