Monitor shows No Signal but CPU works fine

Hi,
My monitor shows NO SIGNAL but my CPU turns on. I tried all the possible ways.

1. Tried removing CMOS and cleaned up.
2. Tried removing RAM and cleaned up.
3. Cleaned up all the possible areas of motherboard.
4. Unplugged all the cables and then re plugged them.
5. Unplugged power cord and then pressed power button for 30 seconds to 1 minute.
6.Removed CMOS and placed it outside for 15 mins and then re installed it .

Nothing works for me. :(

One more thing I noticed that my DVD ROM is also not working. All the mentioned issues started today only and it worked fine till yesterday.

Can anyone of you please suggest what else I need to check before I call a mechanic.