Jim Garrison wrote: > On 6/26/2015 6:44 AM, Richard Owlett wrote: >> Fred James wrote: >>> Jim Garrison wrote: >>>> LCD monitors are not subject to magnetic interference the way >>>> CRTs were, so making a Faraday cage out of aluminum foil will not >>>> work. The fan is causing your power to fluctuate. It shouldn't >>>> be doing that, and if it does there may be a problem with the >>>> building's wiring. You should notify your building management >>>> and ask them to get an electrician to come out and diagnose the >>>> problem with the fan. There's a *small* chance this could be a >>>> fire hazard in the fan. >>>> >>> Jim Garrison This is an interesting thought, and interesting >>> information. One more question ... there are two monitors in this >>> room, about 6-7 feet apart. The one near the outside wall is the >>> one that "flickers" and goes black. The one 6-7 feet further in >>> seems not to be effected at all. Both Monitors are on UPS (separate >>> UPS for each system), and both UPS are plugged into the same wall >>> socket. Does that information effect your thoughts on this issue >>> in any way? Thank you Regards Fred James > Physically swap the monitors (i.e. move them) and see what happens. > If the same monitor continues to have a problem then that monitor > is overly sensitive to voltage transients. If the problem stays > near the outside wall, then it's likely the UPS that has the problem. > For step 2, leave the monitors swapped and physically swap the > UPSes. That should confirm where the problem is. > >> Additional note ... the UPS supporting the blinking monitor also >> supports the desktop machine, and two network devices ... only the >> monitor (as far as I can tell) is suffering. > The desktop machine has a power supply that is designed to cope with > wide input fluctuations of the type caused by other loads on the > input power line. It isolates your computer quite effectively. > The network devices may just not be very sensitive, or their wall-warts > do a reasonable job. > > Note that typical consumer UPSes do not isolate downstream equipment > from voltage fluctuations that do not also trigger a switchover to > battery power. I.e. it's not a power conditioner. > > Based on your comments I think it's more likely that either the monitor > or UPS is the problem, with the monitor's power sensitivity the most > probable cause. > Thank you (all) ... testing that now ... I shall let you know the results Regards Fred James
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