I assume that, from what you are saying, you have tried your Compaq monitor on an older computer and it still malfunctioned? If that is so, I suggest you connect the monitor beloning to the older computer to your Compaq and see what the results are
No I hooked my monitor to my compaq computer then I also hooked another monitor to my compaq computer. Neither monitor worked. Then I hooked my monitor to the old computer and it finally worked. So I know the problem is in my computer somewhere. I just don't want to buy a video card if it is really the whole computer.