Re: Modern myths

From: Jan Gröndahl (
Date: 1999-04-22 11:36:50

On Thu, 22 Apr 1999, Marko Mäkelä wrote:

> On Wed, 21 Apr 1999, William Levak wrote:
> > As you change the values from their optimum level, the image begins to
> > waver and distort.  Getting farther away, you lose sync and the picture
> > breaks up.  Even further, and the driver circuitry (technically known as a
> > ramp generator) ceases to respond to the signals and the screen goes
> > blank.  NONE of this damages the display in any way.
> What about the urban legends that one could damage a PC display by feeding
> wrong line frequencies to it?  I've heard of one friend's friend whose
> monitor let the smoke out only after a few seconds of wrong signals.  Has
> anyone really seen a flyback transformer or some other component that has
> fried because of out-of-specs frequencies?  (Hmm, now when I think of it,
> many PAL TVs keep a little noise when fed with an NTSC signal.)

I tried my rather old (1995?) 17" IBM monitor with 120 Hz at 640x480 mode,
so after five seconds or so I saw smoke which reached half a meter from
the top of my monitor.

I quickly turned off that thing and I was suprised the monitor worked
after that just ok. =) Probably only insulating stuff burned a little.

Name:  Jan Gröndahl
GSM:   040-5631925

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