UPS : when monitor is switched on

[maindola]

I am using a 600 VA UPS (microtek) and 17'' LG monitor. When power goes off, i get enough time to switch off my PC. But if my monitor is off and power goes off and i try to switch on my monitor, my UPS fail to take load .

Guys kindly suggest any solution to this issue as i keep my monitor off most of the time.

Is there any problem with the UPS?
If i change my UPS to 1000VA, will it help?

Thanks

[gaurav_indian]

It's same for me also.I don't think it has anything to do with the UPS.

[rollcage]

It happens on my APC 650va too .. sometimes .. really crazy

[Vishal Gupta]

Its a common problem with UPS.
Me too faced this problem when I had Samsung 15" Color monitor, but when I replaced it with Samsung SyncMaster 510N, the problem was solved!
Now It never restart the pc, whether I switch off/on my TFT at the UPS backup.

[deathvirus_me]

The UPS simply can't handle the load ... generally the UPS rating should be in this order ..

(total PSU wattage + monitor wattage )*1.4 < SMPS rating ...

i.e. consider a PSU constantly drawing 350W .. and the monitor 70W .. so it sums up to 420W ... so 420*1.4 = 588 .. so the min. rated SMPS u'll need should be 600VA atleast ... This is where the modular PSU's come in real handy ...

[janitha]

The explanations of both deathvirusme and anrchist are correct but normally the power factor of a UPS is 0.6 and so a 600VA is not likely to supply more than 360W.
But what I suggest is to buy another good UPS (500 or 600 VA should cost you >2000) and power the monitor through it. This way, you will also get much longer back up time also. And this is what I have been doing
[This may not be required if you plan to go for a TFT}

[ashnik]

Hey guys, if u r turning off the monitor just to save the electricity bill, then don't turn off it. Instead go to power options in ctrl panel and change the Turn off monitor to lesser time, i have kept 10 mins. This won't turn off ur monitor, but it'll make it STAND BY. In stand by mode all 17" monitors consume only 1-2 W. Also if u just move ur mouse then it will wake up w/o restarting even on UPS batt.

[maindola]

Thats a wonderful piece of information....
Thanks guys......

[Rollercoaster]

when a monitor is switched on from 'power off' state then it needs huge currents to charge its capacitors for a few microseconds. and a UPS cannot provice such currents. the fault is not in the UPS but in the battery.

a ups uses a small 7 amp battery which i incapable to provide such huge currents in such small time.

it is same as when a A/c(or a big screen crt TV) is turned on. u can see the lights in the same room blink for a second. it is the initial power requirement that is too high for such devices.

the only way to avoid this is to let the monitor go into power saving mode. as in this state the capacitors are kept charged.

BTW this might also switch off ur UPS if the battery has gotten OLD.

[unni]

I overcome this problem with a simple program called nircmd (about 75 kB) available at http://www.nirsoft.net/utils/nircmd.html . It is a command line utility that allows you to turn off your monitor, eject and inject CD drives and a lot more. What I do is create a shortcut for the program with the required command in the start menu and assign a hot key to it. So if the power goes while the monitor is switched off, I press the hotkey, wait for a few moments and switch on the monitor. It will be in standby mode. Now you can safely press any key or move the mouse to bring it out of standby so that you can turn off your system after stopping what's going on. To make sure that the program was launched before you turn on the monitor, you can make it to produce beep sounds.

[Akshay]

Facing the same prb...

@rollercoaster
U have finally made us understand y exactly dis happens...

[nil_3]

Another possible solution is to buy a 17'' TFT monitor. With 40W at running and 1W at standby requirement it will not cost much on 600VA UPS during power-cut.

[shaunak]

Cathode ray tubes require large ammounts of energy to start emmiting electrons [thats what forms the immage] and a high PD to continue emmision. While your UPS can provide to PD requires it cannot provide the power. [its drawing from a battery after all].
best solution is to buy a LCD monitor; youll get a greater back up time due to less power usage and as a added plus your eyes will not feel tired after sitting on the computer for a long time.

[JGuru]

CRT monitors are the main power drawers from the UPS!! I use SamSung 17'' monitor,
SyncMaster793s with APC UPS. I never had a problem like the one you guys mentioned!!