HP Prime not charging/cannot connect to computer

[WilliamLi0623]

Hello everyone, I'm having some problems with charging my HP Prime and connecting it to my computer.

The story began from yesterday. As I unplugged the calculator from the charger, I found it was black screened, and I cannot power on it. I connected it back to my charger, and it was white screen flashing. I then unplugged it and picked out the battery and connected to my computer. It powered on. And then I put the battery back in, and it also boots up. However, the battery level was only 25(means that it didn't charge). In the debug mode, I found the voltage of the battery is 3.63V.

Today, I tried to charge it again. I connected it to my computer to charge. In my memory, the screen should light up automatically, but this did not happen. The system is also not showing any information that it is charging. Then I left it plugged in for several hours. After I booted it into debug mode again, I found that the battery voltage is 4.19V, which means it should be charged. The system also shows it is 100% now. I then tried to connect it to my computer with HP Connectivity Kit. I thought there should be a notification when I plug it in and there should be a HP Prime showing up in the explorer. However, neither of these happened. The HP Connectivity Kit cannot recognize the calculator either.

Does anyone have any ideas about what's wrong with that calculator? I really don't want to buy a new one since HP Prime G2 is really expensive.