Hi, I have a problem
There is a major problem with the fan's electronic board. There is most likely a shorted capacitor, or some sort of fried transistor somewhere. depending on your electronics know how, try troubleshooting the circuit starting with it's power supply/input. but depending on the price of the fan, and the amount of aggrivation, I would just get a new one. Remember, most of the newer appliances today are ment to only last a few years, then die. I don't care what it is. all the companies want to do is make them as cheaply as possible, so they can sell more of them, and make more money. so don't be surprised if you can't fix it. some things are just not fixable.