So for a better diagnosis:
- try another monitor with this laptop
- try this monitor at some PC
Tell your results.
Most monitors have a self test feature to determine whether the issue is coming from the monitor or somewhere else. So, disconnect the monitor completely from the laptop. Now turn it on. If your screen is showing anything at all the problem is not with the monitor itself. If it remains black it is the monitor.
If it's not the monitor, I'd replace your cables first, sometimes pins get bent enough they are no longer making the right connections to display a picture on the screen.