1. When there is no cup on the top, it is normal for the 3 lights to flash together
2. When there is no cup, if one light is turned on, it means that the bottom gravity switch is pressed by something.
3. When the cup is placed on the top, the 3 lights flash together, the bottom gravity switch is not pressed, maybe the cup is too light or no water in the cup.
4. Three lights flashing back and forth, the reason is insufficient current, please make sure that your adapter is above 5V-2A
5. There are two keys only can be pressed, rightmost key and leftmost key. The other keys can’t be pressed. 
6. Please use the flat-bottom cup, do not use concave bottom cup
7. Please make sure the input voltage and electric currect ≥ 5V 2A

Solution:
1. Try to press the bottom gravity switch 
2. Use 5V-2A adapter, original USB cable

· 【Keep Beverages Warm】
-The cup warmer mainly keep your coffee, water, milk, tea, and other beverages at the perfect temperature for a long time, wherever and whenever, you can enjoy your favorite drinks at the perfect but not-too-hot temperature.
· 【Use Suitable Mug】
-Use a thin-walled, flat-bottomed mug will have the best warmth retaining performance
· 【Best Gift Choice】
-Beautiful and compact design, keep your beverages always warm, It will be your best gift choice to show your care to your families, lover or friends on Valentine’s day, Thanksgiving, Christmas or other special occasions to show your cares.
【Attention】
1. we don’t recommend use concave and thick bottom cup, the heating will be slow and bad heating result
2. This is the cup warmer only, not the electric kettle, it can not boil the water, it mainly slow down the cooling speed of hot water, keep the hot water warm the whole day.
3. If you want to heat the cool water, you may have to wait for 30-50 minutes, or even longer, the max temperature will be 50-55℃, the longer you wait, the closer you will get to 55℃. The heating speed depends on the thickness of cup bottom and water capacity
4. The product doesn’t include the adpater, please use your phone adapter or other USB sockets, and make sure the adapter output power ≥2A, or it can not get enough power and the heating will be slow and weak.