|How old is the Dell monitor ?|
Is it an LCD monitor ?
Some monitor models display a message when they are receiving no video, e.g.when the video cable is not connected but the monitor is powered on, or when the cable is plugged in to the computer,the monitor is powered on, but the computer is not producing video.
If you're seeing a message, there's probably nothing wrong with the monitor.
State the model of the IBM (or more likely, Lenovo) computer
If it's a laptop, several things can cause no video at all on an external monitor.
For some laptops, you don't need to do anything to get video on an external Monitor.
For others, you need to press a key combo to toggle the display to built in video / external video / etc. - see the User's or Owner's manual.
If it's a desktop computer, if you have both one or more ports for onboard video - video built into the mboard , and one or more ports on a graphics card in a slot, in MOST cases, when you install a PCI-E X16 card in a slot,the onboard video is automatically disabled and you will get no video from it's port(s).
The only exception is if you have a desktop computer and your main chipset supports Hybrid video - both the onboard video and the video card in the PCI-E X16 slot being enabled - producing video - at the same time. If the card does NOT have one of the few video chipsets that are supported by the Hybrid video feature of the main chipset, usually by default the onboard video is working but you get NO video from the card in the slot - in that case you must change some bios Setup settings.
Are you getting no video at all,
or you DO get video while booting but NOT after Windows starts to load - the latter is usually easy to fix.
Try the monitor connected to a different computer.
Try a different monitor connected to your computer.
The monitor must be plugged into AC power and the power button on the monitor must make the power led light up on it, of course.
It's usually one color ,e.g. green, when you first power it on, the same color when it is getting a video signal from the computer, another color, e.g. yellow or orange, when it's video cable is not plugged in after a short time,or when the computer is NOT outputting video from the port you have it connected to.
"Last night the computer was on "standby" and when I went to awaken it, the monitor stayed black."
You must do the right thing to "wake up" the system.
Assuming you did, if there is nothing else wrong, if you have re-loaded Windows from scratch, you MUST load the main chipset drivers after Setup has finished to make sure that Windows has the proper info about how the mboard's main chipset supports ACPI features, including Standby, Hibernate, and sometimes Restart, otherwise those features may NOT work properly.