When your computer is on (the power light on the tower is lit) but there is no image on the monitor, check the following:
All cables are securely attached to both the back of the computer and the monitor.
The monitor has the power on, you should at least see the power button lit yellow or blue.
Try restarting the computer, you may have to hold the computer tower's power button until it goes out.
What To Do If The Above Is Not The Problem
If you have checked the above possibilities and you still have no picture, read on.
Our computers (Black Gateway) have been repeatedly known to start without displaying an image on the monitor. This is not a problem with the monitor, it is a problem with the computer not starting properly.
The first thing to try is pulling the black power cord from the back of your computer tower and waiting at least 5 minutes. This discharges built up electricity in the circuit boards allowing the computer to "forget" its last state of operation. Plug the power cord back in and try to restart the computer.
Typical Power Cord
Power Connection on Computer Tower
My Computer Beeps When I Turn It On
If when you turn your computer on the computer beeps, the following operation usually solves the problem.
Disconnect the power cord from the Computer Tower Case.
Open the Computer Tower Case. This is usually accomplished by removing a screw or two and sliding the side of the case off. Sometimes a handle or lever is provided.
Locate the computer's memory modules.
The memory modules should be removed by pressing outward on the retaining clips at the ends. Then the modules should be reinstalled by carefully aligning the module in its slot making sure it is oriented the same as it was before it was removed. Then firmly, but carefully, press the module down until the retaining clips return to the upright position. Repeat for both modules.
Sometimes removal is not neccessary and just a "wiggle" while pressing firmly down is enough.
Close the Computer Tower Case and reconnect the power.
Hopefully, your computer will start correctly after this procedure.