My pc is not powering on neither its screen working.

@erickukumu you say that your "pc is not powering on" but then you say it is overheating. Does it overheat without turning on? If so, you have a major short circuit on your motherboard or a really bad battery. For now, you do not want to try to power your computer on any further, since that may just cause more damage. We will need to know the exact model number for your computer. There are a lot of different models in the Lenovo L series. You want to remove the bottom cover and then take some really good, well focused pictures and post those with your question. That way we can see what you see and hopefully find out what heats up.

Bottom line = No power, fan isn't working, no screen, no lights from the keyboard and overheating = short circuit (motherboard or battery are the prime suspects)

Adding images to an existing question