[rescue] Power question...

Dan Sikorski me at dansikorski.com
Mon Jan 12 22:50:55 CST 2004

Carl R. Friend wrote:

>   On Sun, 11 Jan 2004, Nathan Raymond wrote:
>>I realize this is somewhat off-topic, but I figure you folks are some of
>>the most experienced people to ask this question: what would cause
>>computer monitors (any monitor, hooked up to any computer) to jiggle at a
>>refresh other than 60Hz?  I'm talking serious jiggle, and at any refresh
>>above 60Hz.  This has been happening since I moved to an apartment in
>>Cambridge, MA a few months ago, and it happens to all my monitors (four
>>different ones, three different brands), hooked up to any computer.  I
>>only get a stable image at the eyestrain causing, headache inducing
>>refresh rate of 60Hz.  I've tried outlets on either side of room, no
>>difference.  I don't have any sort of UPS, just some high quality power
>>strips (and this happens on more than one power strip, so I know it's not
>>the strip).
I've dealt with this one before too....

>>   This is going to sound completely off-the-wall, but there are a
>>couple of office in the building I work in where conventional CRT-
>>based monitors are just about useless and just for that reason.  We
>>know that there's a UPS (to power our telephone switch) just adjacent
>>to one of the rooms, and suspect that there may be a power feed in
>>a conduit near the other office.  My suspicion is that you've got
>>a large source of magnetism somewhere in your close vicinity (are
>>you near the main A/C compressor motors?).  Take a quick squint
>>around your environs.
>>   How did we fix the problem at work?  We installed flat-panel
>>displays for the folks in question.  As an aside, the problem
>>isn't a _flicker_ per se, but rather a "wobble" in the display.

In the situation that i dealt with, there were some large transformers 
on the roof of the office.  This was probably 4 years ago, so a LCD 
monitor wasn't really an option.  I swapped the guy's monitor out for a 
better one so that he could run it at 120hz, which took care of the 
problem.  If your monitor will support it, i would suggest that.  
Otherwise, it's time to track down where the interference is coming 
from.  Good luck!

    -Dan Sikorski

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