Before you proceed flashing / hard resetting your phone / tablet make sure to back up your important files if possible. Because we care about your data.
We also suggest that your battery should be atleast 50% or better to have it fully charge, lower than the said value may cause unwanted result, such as bricking your phone / tablet rendering it unuseable. This is very important in flashing your phone / tablet. Use original USB cable as possible.
Files that you downloaded should not be corrupted, if ever the file is corrupted you might brick your phone. Or the flashing will start.
Drivers are very important specially in Spreadtrum Chipset, having an Spreadtrum SPD6610 (non android devices) driver will not work in SPD6820 (android devices).
If you are using laptop to flash your phone, make your that it has enough charge. If your laptop shutdown when your flashing your phone/tablet, you'll end up bricking your phone. Sometimes you can still recover your phone just flash it again and your phone will boot up again. But that is just a case to case basis, if your phone / tablet is deadboot (totally dead, erased all program in the chip) you can't recover it, you will need to seek professional help (technician).
This is the STOCK ROM of MyPhone A818i, this is flashable via SP Flash Tool. You can find SP Flash Tool in Tools corner in my Blog which is in the right side of my blog.
Or Here --- >>> SP Flash Tool
You can refer to this blogpost of mine how to flash via SP Flash Tool
SP Flash Tool Reference/Guide
You can find the File below
Download Here << --- A818i Stock ROM