Why does our office Polycom system go dark when no one moves?

The IP 335 is an entry level phone so it is doubtful that there would be anything like a fuse in it. From what you've described here I would say the phone is fried. Moving forward I would recommend to always keep your important electronics on a good quality surge suppressor and/or a UPS. Good luck.

Can you try the screen in another computer? I beleave the screen goes into power saveing mode when there is no input signal, thats what both my screens do.

Is your computer working?

off the energy save mode...it goes revert of ur action...re-install opreating system..is it work? clearfy

Check the energy save settings and see if the monitor is set to shut off after a certain amount of time. Also if the laptop battery gets low it may start to turn off the monitor to save energy. Are you using the computer on a/c power or battery power when this happens? As far as fan controls the settings are usually in the bios but you can sometimes install software that will control the system fan. The BIOS system menu is usually available by pressing delete when the computer boots up(some computers are different button).

Switching itself OFF to me it means even the LED light at the front goes OFF. If that's the case, you may have a hardware problem. However, if the LED changes color, chances are your monitor is gone to "sleep mode" in order to save you money on energy. If the latter is the case, simply moving the mouse of pressing any key on your keyboard brings the display back. Try that.
Energy saving is controlled by your Operating System, Windows or Mac. Look in the Control Panel for Power Management or similar category. In Windows, these settings can be found and are related to Screen Saver. Look there first.
Good luck!

It appears that you do indeed have the system on energy save, go back into set up and un check power save mode.

Try maxing out your power save timers. Here are the instructions. I suspect the machine is going into power save mode to quickly. Here is how you do that.

NOTE: To save energy, the printer enters a power saver, low-energy consumption mode after a predefined period of time since its last activity. In this mode, most printer electrical systems are shut down. When a print job is sent to the printer, the printer enters the Warm-up Mode. You can also warm up the printer by pressing the [OK] button on the Control Panel.
If the printer is going into Power Saver mode too often and you do not want to wait while the printer warms up, increase the length of time before the printer goes into the Power Saver mode.
Modify the timeout value:

1. Press the [Up] or [Down] arrow button on the Control Panel to select [Printer Setup] on the Display Screen, and then press the [OK] button.
2. Press the [Up] or [Down] arrow button to select [Printer Controls], and then press the [OK] button.
3. Press the [Up] or [Down] arrow button to select [Power Saver Timeout], and then press the [OK] button.
4. Press the [Up] or [Down] arrow button to select the required timeout value (30 - 240 minutes), and then press the [OK] button.
   
   NOTE: Select a larger timeout value to extend the length of time before the printer goes into the Power Saver mode.
   
   
5. Press the [Up] or [Down] arrow button to select [Exit], and then press the [OK] button to return to the Main screen.

I had the exact same problem but it is fine now! :) And this is how you solve it .....you press the power button (single press), and a series  of options come up...if you scroll down them you will come across a 'deactive power save mode' option, click select and this should sort it out! 
Hope this helps! :) 

The monitor is not receiving signal from the computer. Is the power light on on the computer? If so - press and hold power button on computer until the power light goes off, then press again to restart. If the computer starts and you still have no picture it is most likely a video card or motherboard problem.

try going into the controlpanel,display,then on the screensaver tab click on the power button and check settings