9 times out of 10 the problem is with either the power supply to the plug or there is a problem with the cable. check the plug to see if there is a broken wire inside or the cable itself may have a broken wire inside. plug the mixer into a different outlet, maybe the outlet you normally use is faulty. other that that you don't have much choice that to take it to an appliance repair shop.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix blenders/mixers.