the razer laptop power is not charge

The laptop is working well all the time. I do not know why the power was not charging. it happened few days ago, and it was fixed after I restart my laptop. but the second times when this happened again it was not fixed even after I restart my laptop. I searched the website and found the solution, unplug the power adapter for 30 seconds and then plug in back, it works. Then after few minutes, the screen become dim and I saw the power icon was turned to unplug, but it only lasted for few second, after that the power icon was turned to plugin, the screen turned back to normal. This was stranger things which never happened, I did not unplug the power.