O+ 8.52 8GB variant stock rom to unbrick your phone

The firmware is for O+ 8.52 8GB variant. I haven't tried to flash this ROM in a O+ 8.52 only. To check if you O+ 8.52 is the 8GB variant. You go to settings and check it in About Phone. Or you can check it at the back of your phone, it is somewhere near in the IMEI.

"Download these files"
Firmware Here -->O+ 8.52
VCOM Driver -->VCOM Manual
Alternative Driver --> AutoInstaller

SPFlashTool --> LatestVersion 

"Use WinRar or 7zip to extract the firmware"
"Extract the files to your desired folder"
"If you encounter error in flashtool, use different version of it."

"I suggest to use 32bit Windows OS for compatibility of the driver"

Installing Driver with AutoInstaller

First try the Alternative Driver, which is the AutoInstaller. Just open the install.exe then it will automatically install the driver. To fully check if the driver is correctly installed in your computer. 

Follow these steps:

1. Turn off your phone (always powered off is a must)
2. Press and hold volume up or down, or you can simple press the two button
3. Insert your USB cable without releasing the VOLUME button(s).
4. In your computer, it must detect your phone and it will install the MTK Preloader or Mediatek USB VCOM driver.
5. Repeat 1 to 4 if it does not detect your phone.
6. If MTK Preloader/Mediatek USB VCOM Driver is installed you are good to go in flashing your phone ^_^

Reference Video using Driver Auto Installer (watch in HD)

Installing Manually using VCOM Driver

When installing it manually your phone must be turned off, then connect it to your computer/laptop while pressing VOLUME UP or VOLUME DOWN. This will detect and look for the driver.

 1. This is the first time that you will connect your phone and it will search for the correct driver.

2. Check include this location ... ... and click on browse. Look for USB VCOM Driver and Click on 2K_XP_COM folder if you are using Windows XP or Win7 for Windows 7 and then press OK when you are done picking the right folder for the driver.

3. If the driver is successfully installed MediaTek DA USB VCOM will appear in the New Hardware Wizard.

Video Installing VCOM Driver (please watch in HD)

"Your Phone must be turned off when you are ready to connect and flash your phone"

Flashing

1. Launch FlashTool (flash_tool.exe)

2. In Flashtool, Click on Scatter-Loading, and load your scatter file. (see example below)

Reference Video Using FlashTool version 5.xxx (watch in HD)

 3. After you load the file, press Press Download to Flash your Phone.

4. After you press Download Follow these steps

• Turn off your phone (always powered off is a must)
• Press and HOLD volume UP or Down or you can simply press it simultaneously
• Insert your USB cable without releasing the VOLUME button(s).
• Keep on repeating until Flashtool detected your phone.

5. If successfully detected just wait until the progress bar reaches 100%. If your phone did not automatically turn on after flashing, remove battery and USB cable. And put back your battery then turn on your device.

"Hard reset your phone after flashing"

Some workarounds:

If you encounter PMT_Changed error here is what you do:

In Latest version of Flashtool

1. Load the scatter file
2. Choose Format all + Download (Underneath Scatter-loading file)
3. Then Click Download and wait until it is done flashing

For Invalid IMEI:Your Phone/Tablet must be rooted first
Restore yong IMEI in MTKDroidTools version 2.5.3. You will have this error when you format your phone in Flashtool as I had experienced. To restore download MTKDroidTools version 2.5.3 After you extract the file. Open the green robot, you must enable the usb debugging in your phone. It is usually located in Settings>Devoloper Mode then look for usb debugging. After enabling it. Connect your phone in your computer then in MTKDroidTool click on ROOT. Wait for it to finish, then Click in IMEI/NVRAM, input 15 number in each box. Then click REPLACE. Then click Reboot or you can manually turn off your phone. Then turn your phone on again. You can see that you have fully restored your IMEI.

I hope this tutorial help you. Please drop a comment if something is not clear to you.