surface

Step 1: Press and hold the power button on your Surface for 30 seconds and then release it.
Step 2: Press and hold the volume-up button and the power button at the same time for at least 15 seconds and then release both.
The screen may flash the Surface logo, but continue holding the buttons down for at least 15 seconds.
Step 3: After you release the buttons, wait 10 seconds.
Step 4:
Press and release the power button to turn your Surface back on.


* Solution
1. Discharge SP4 as possible as you can. Let SP4 boot loop alone. (in my case I've saw boot loop for 6 hours. painful)
2. It gets hot. Be careful for the heat radiation.
3. When it's fully discharged, it'll be powered off eventually.
4. Turn on SP4 again, and you can see a 'Big LOW BATTERY Icon' followed by 'Surface' logo. (and then powered off automatically)
5. Seeing ' Big LOW BATTERY Icon' is IMPORTANT. It makes a big chance to exit from the boot loop.
6. Try #4 repeatedly to discharge it as far as you can.
7. If it's entirely discharged, pressing the power button takes no effect.
8. OK. Now charge SP4 at least 15 minutes.
9. Push the power button. Voila~!


另外是放電到整台關機，然後充電１５分後再開機