First check your surroundings and the given parameters, i.e. find out if there is a general power cut in your neighborhood or if the problem is to be found in your apartment only. Just give it a moment’s silence. If you still can hear your neighbor’s television at an usual piercing sound level, go to the window and see if there is light in the opposite windows.
This confirmed, there is probably no general power cut anywhere near and the problem has to be found inside your apartment, i.e. it’s either a blown fuse or – most likely – your electricity card (!) is out of funds and needs a recharge. In China electricity is paid according to usage and paid for in advance. Once the charged card is empty – usually in the middle of the night when the usage is high – you have a blackout. You can recharge your electricity card at all banks and many tobacco/alcohol shops. If it is in the middle of the night though, there is no place to do that – get your candles out, tell each other ghost stories and wait for the banks to open at 9. When you recharge the card, usually RMB 200 to 300 will go a long way. Dip the charged card into your E-meter (in or near your apartment) and wait until the zeros turn into a number. Push the fuse up. Done! Make sure the landlord shows you where to check your electricity left and how to use the card.