Wow...So sorry to hear that.|
Make sure to back up all your stuff, because chances are if you send it back, you'll get it back factory reset-ed.
My advice would be to contact Chuwi and let them get you to send it to their EU repair center (If you live in Europe obviously). They will repair it for free and you will have no risk of damaging extra stuff whilst trying to do it yourself, what WILL result in your warranty being void... if they find out, that is.
I strongly recommend everyone to stop using the stock PSU as I simply do NOT trust it. People have seen it break, smoke, ... Just get one that is in the Hi13 recommendations thread.
I hope this issue stays limited to few people.