dell optiplex 760 will not turn on

[Lynne Desrochers]

Someone complained about a monitor this morning. They have dual monitors and I had just switched out this one, so while the computer was on I switched the left for the right one. After that the mouse and keyboard weren't working, so I had to shut off the power strip, now I can't get the darn thing to boot. As soon as I turned the power strip back on the power button went green and lights lit, fans blew but it didn't ever turn on the monitors, they kept saying "no signal".
I've tried pulling the power cord for a minute then plugging it back in and it immediately starts without pressing the power button, but doesn't actually turn over, and you don't see anything on the screen. Is there a reset somewhere? Did I put it to sleep? What are the magic words?
Right now it has a green power button, network light is green, 2 + 4 are green and nothing (no signal) on the monitors. It's plugged into a different monitor / mouse / keyboard than this morning.
Thanks!

[Gene Foraker]

The magic words are "Don't unplug or plug in monitors which the machine powered up."

I think I'd start with swapping in a spare video card from another machine to see it you blew the card. 

[Lynne Desrochers]

Thanks sailor Gene, i know that now. I reseated the video card and all is well again!
But seriously, i've swapped a monitor on the fly before. Is this really bad? Or just a bad day?
Lynne

[Bob]

My experience bad day coincidence.  Nothing more..   

[Lance Bateman]

I'd suggest never unplugging and plugging in anything if the machine is turned on.  You have to remember these things use low amounts of electricity, and are also sensitive to variations in power.

[Ian Blundell]

But the computers and/or operating systems are supposed to be plug & play.  Why shouldn't you be able to power off monitors or other peripherals?

[Jeff Zylstra]

Had this happen last week.  You'll need to unplug everything attached to the computer and count to 10, turn the computer on first and then all of the peripherals.  Don't ask me why, but these plug and play and power sensing devices are very finicky about the the order in which you boot up, and there is a very brief period of time when the video card and monitor check for signals.  If you miss that small window of opportunity, you have to do this procedure.  Good luck with it.  If it doesn't happen the first time, try it again until it does, and don't try to cheat!

<edit> You'll need to unplug everything attached to the computer and including the computer, and count to 10, turn the computer on first and then all of the peripherals.  That's better.

[Lance Bateman]

I don't think it's so much a matter of powering off attached items, as actually detaching them and then attaching something while the computer is on and power is coming in.

But yes, just like removing a stick drive without using the appropriate "remove remote device" approach, anything else (especially anything with memory being used) can become a problem if you just remove it.

But the computers and/or operating systems are supposed to be plug & play.  Why shouldn't you be able to power off monitors or other peripherals?

[Gene Foraker]

Plug and Play with the computer turned on only means things connected with usb or perhaps firewire.    USB memory devices should first be removed electronically before unplugged.  Just like Lance said.  Do you have an iPod?   It instructs you to disconnect before removing the connection.

Plug and play also works with other items when the PC is powered down, The term just means that the drivers will should automatically install and load.   Remember the old days when you had to have a driver disk to hook anything up?

[Jeff Zylstra]

You are correct.  Plug and play was not what I wanted to say.  This is a function of the new"green" devices in that they will shut down the monitors and also the video card output when they don't get the proper signal in that short time span when Windows looks for the signal.  This is a maddening issue because once it gets this power state stuck in Windows, it demands a power shutdown of everything attached.  It reminds me a lot of the old IRQ issues where if you left a printer on when you shut down the computer, the computer wouldn't want to come back up when it was powered on.