Re: screen flicker: probably not X related

Pippa Reeves is a darn nice person I don't care what anybody says!
>
> What is inside the section of the PC nearest the monitor?....
 Power supply cooling fan, cpu fan, 2nd cooling fan (on inside/front of case), 
cooling fan on nvidia card.
> I would almost make a bet that the wobble effect on the screen is caused by
> the changing magnetic field surrounding one of the PC's fans. These pesky
> little devices have permanent magnets in them, as well as having AC driven
> electromagnets. As the permanent magnet is spinning and the electromagnets
> fed with AC power from the fan's internal electronics both will have
> changing magnetic fields generated.... If the fan is not magnetically
> shielded properly this would make you CRT screen go crazy.

I do not understand what you mean "AC driven electromagnets". While I have AC 
into power supply (so maybe PS fan is AC) the three other fans the fan on the 
nvidia card draws power off card which is DC and the two cooling fans draw 
power off mobo which is DC
>
> You could try unplugging the fans one at a time and power the computer up
> for a few seconds to see which fan is causing the problem.
 tried auxiliary cooling fan for no change and of course when I pulled nvidia 
to test onboard graphics that fan was removed.

> I very much doubt it is going to be the power supply circuit itself as the
> transformers used in these operate at an extreemly high frequency, and
> usually have a 'shorted turn' type copper shield to keep their magnetic
> field under control. It could be the fan in the power supply though, these
> are usually a 12 Volt DC powered motor as described above.

I am left with heatsink fan on cpu which I'd rather not disconnect atm and I 
think rearrangement or shielding might be the answer although my wife wants 
all her baking trays back.

>
> Be very careful if you decide to open the power supply box up.... there are
> LETHAL voltages present inside that metal box!
>
> Replacing a fan with a better quality unit is not usually an expensive
> exercise.
>
>
> Good Luck,
> Pip
>
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-- 
Cheers,

Rick Miles

Movement stopped is no movement,
and rest set in motion is no rest.

Written on Setting Orange, the 60th of Chaos, 3171 
http://www.members.optusnet.com.au/~rickfrm/