Computer Black Screen Problem

When the first time I encounter this problem i don't know what will i do... i search to the web what causes this black screen and i found out there many hardware that causes this problem.
The following are some example only on how to troubleshoot this black screen:

1. Check the video cable if it is properly connected then restart the computer. if still black screen appear follow step 2.

2. Try a known good Monitor and restart your computer. if still black screen appear follow step 3.

3. Try to clean or replaced the memory with known good memory and restart your computer, if windows appear your memory is damage or unclean. if still black screen appear follow step 4.

4. Try to remove the hard disk it is maybe shorted and restart the computer without the hard disk, if the bios appear your hard disk is shorted. if still black screen appear follow step 5.

5. If you have a known good Power Supply try to replace the old power supply and restart the computer. if still black screen appear follow step 6.

6. If you are using a video card try to clean or replace the video card then restart the computer if still black screen appear try to remove the video car, put the video cable to the build in video port then restart the computer. if still black screen appear follow step 7.

7. If you know how to remove and clean or replace a processor do this. Remove the processor then clean it or replace it with the same model also clean the heat sink and the fan of processor then restart the computer.if still black screen appear follow step 8.

8. Try to replace the mother board with a know good mother board with the same model.if still black screen appear follow step 9.

9. Its time for you to ask help to computer troubleshooter..