What would cause an entire suite of TFTs to start flickering (frequency/refresh)?

[Ben_Stanton]

Weird one.

 

All 20 TFTs in this room (apart from 1) have all started flickering. They were all set to 60Hz but to reduce (or speed up) the flicker, I have to set them to their maximum of 120Hz. It is still slightly noticeable on some. (if you look sideways/peripheral)

 

What could have caused this? Power fluctuations/instability? Flourecent lights (no lamps have been changed)?

 

Any ideas greatly welcomed...

 

Ben

[dalsoth]

One side of a room did just this when we put flatscreens in next to the library security gates. That an issue with you? Any other similar electrical stuff nearby?

[machin05]

Maybe something electrically dirty plugged into the same circuit, and old fan or more likely a heater at this time of the year.

[timzim]

My thoughts exactly. Either a dicky transformer somewhere or a load of heaters on the same ring, dropping the voltage. Try unplugging all other electrical equipment (especially power adaptors) in the same room until the flicker stops. Since the flickering started recently try to find out if anything new has just been introduced to the circuit - if other rooms are on the same circuit/phase check them for fan heaters (since it's just got cold).

 

If you can't find anything obvious try shoving a voltmeter across the room's supply to see if you've got an obvious power fluctuation or if the voltage is abnormally low. If so get your electrician in or you'll damage your equipment in the long run.

 

Disclaimer: if you electrocute, burn, maim or otherwise injure yourself or anyone else by following this advice that's your problem

[Ben_Stanton]

I have already been round unplugging things. I'll carry on but am sure I have been to all areas that are on this ring/phase/DB. All apart from the gap students living area upstairs - that could be a possibilty (dirty foreign appliances - probably French).

 

Also, my UPS emails me on a nightly basis telling me the power is compensating for power irregularities...so i'll look down that route too.

 

Thanks guys...

[Jamo]

The flickering is unlikely due to the pixels in the screen but more likely to be the lamp in the screens. I agree with a power issue maybe low voltage.

 

I had an energy saver bulb which I put in a dimmer once, was an interesting strobe effect, but sounds like it could be a similar problem with your screens :S (Maybe not a dimmer switch though )

[StewartKnight]

What would cause an entire suite of TFTs to start flickering (frequency/refresh)?

 

Students

[jedmondson]

What would cause an entire suite of TFTs to start flickering (frequency/refresh)?

 

Students

 

as always?

[machin05]

Could it be the sheer number of monitors themselves?

 

What happens if you go around the room and start unplugging the monitors one by one?