Take the needle, and try to clean it from the top of the nozzle block.

In some case, jammed filament will not come out free. At this case , increase the nozzle temperature to 280deg and remove the nozzle cooler fan.

And try to clean the nozzle from the top with the help of a needle and a nose plier.

If the nozzle is again not clean, try to clean the nozzle by removing the nozzle tip with the help of a nose plier and spanner. Again clean it with the help of a needle.

NOTE: Be careful while removing the nozzle tip. If you extract more pressure on the nozzle tip, it may break. So be careful while doing it.