Fluorescent  lamps use a ballast which will emit a magnetic field that can
distort a monitor picture or a radio transmission however this is the first
time I have heard of a ballast actually damaging a monitor. A halogen light
does not require a transformer although a twelve volt transformer is often
used for energy efficiency.
It is always a good idea to keep any devices that produce a magnetic fields
a foot or so away from your monitor to avoid picture distortion.
Mark

>Be sure no fluorescent or halogen lights are nearby either.  They use
>transformers which will mess up a monitor.   I had two monitors replaced at
>work because of a fluorescent lamp that was on (without a bulb in it yet!!)
>and it made the monitor jittery.
>Fred Hahnel

>
>>I have a problem with a Princeton Graphic Systems EO70 17" monitor.Actually,
>> >I am not totally sure it is the monitor. Sometimes -- not all the time --
>> >after operating for several hours, the display begins to jitter. It
>>> >Bryan S. Tyson