...swapping in a known "good" monitor from a friend or family member..It might be just the cable or the monitor itself. On the other hand, if it's related to your other post HERE, then we need to know a lot more information about the computer...The operatings system, age of the computer, whether you've scanned it for spyware and viruses, etc. The more information you give us, then better informed our answer will be.
Hope this helps.
i get a message when i turn on my computer no signal please check video cable even though the cable is plug in properly. what is the problem
my computer is a soniview
pentium 4 processor
thats all i know