If you happen to have bricked your Cube U55GT C8 then you might well find the guide below, and the links provided, to be of some use. While it is a fine device with a great screen my particular one really didn't like factory resets as they essentially broke Android, causing there to be little or no UI left once the resetting was complete. It was very strange and many tech people were confused by it. While I never found out exactly why that used to occur I did find out how to reflash Android on to it even when it seemed as if the device had become bricked (dead). Much of the appreciation for the information below should go to a friend of mine called Nick for going above and beyond the call of friendship to help me out with fixing mine, which in turn has allowed me to put together this guide.
Tools you may need:
Before you follow the steps below it is assumed you have a knowledge of SP Flash Tools and of how to replace drivers within Windows Device Manager. This is not meant as a full tutorial so please refer to other widely available guides on these matters before proceeding with this if you are unsure. This guide is for Windows only I'm afraid!
A - Firmware and SP Flash Tools software: http://chinagadgetsreviews.blogspot.gr/2014/10/download-latest-android-kitkat-442_1.html or http://www.mediafire.com/download/22yzk4cpkc7ebck/U55GT-C8_V1.0_20140902.rar
A - Firmware and SP Flash Tools software: http://chinagadgetsreviews.blogspot.gr/2014/10/download-latest-android-kitkat-442_1.html or http://www.mediafire.com/download/22yzk4cpkc7ebck/U55GT-C8_V1.0_20140902.rar
B - Detailed guide on Mediatek USB drivers: http://laurentiumihet.ro/technology/sp-flash-tool-mediatek-mt65xx-drivers-download-and-installation-guide-including-bricked-devices/
C - (This page was very useful as well even though the author refers to Windows 10: http://laurentiumihet.ro/technology/windows-10-mtk-vcom-usb-drivers-for-32-64-bit-drivers-installation-tutorial/)
D - Nirsoft USB Devices viewer is free and allows you to see what USB ports are active and connected. It proved very useful for this as it also tells you the name of the connections in a handier way than Windows own Device Manager: http://www.nirsoft.net/utils/usb_devices_view.html
Follow these steps:
1 - Make sure you have the right Mediatek drivers installed on your computer. The ones on the website link B, specifically one named MDMCPQ (for Windows 7), worked for me. If you downloaded the firmware from the Mediafire link the drivers are included within the folder "MTK Drivers 32 bit and 64 bit..." Search for "Alcatel xxxxxx" in Device Manager as Windows installs a driver for the tablet automatically and it is, obviously, the wrong one. Replace that driver with the Mediatek driver.
2 - The connection will appear and disappear frequently within Device Manager but this is normal. On my install it came up as Mediatek MTK (Com 13) or something like that under Network. You can check more details using Nirsoft USBDevices software through the website link D above. If all is going well you should see "Mediatek DA USB VCOM Port" and "PreLoader USB VCOM (Android)".
3 - Open SP Flash Tools, ensure it is set up correctly with the right scatter file etc. The scatter file is located in one of the folders in the Firmware folder you will have downloaded from web link A above. You may have to look for it yourself - it is a text file (Notepad format) called MT6592_Android Scatter).
4 - Keep the tablet plugged out and when the scatter file is loaded up and ready to go click on the dropdown menu below the scatter file address bar. Select "Format+Download".
5 - Click on the big "Download" button and then connect the USB cable to the tablet. Ensure that you do this when the device has appeared in the Device Manager window (remember it will appear and disappear every few seconds so keep an eye on it).
6 - Watch the progress bar until complete, disconnect the tablet, power up (it will take longer than usual for the first boot).
7 - The tablet will now be in Chinese but you can switch back to English easily by swiping from the top-right-corner of the screen and going into the menu structure (you'll find it eventually!).
8 - If the tablet had previously been rooted you can download the KingORoot apk (not available in the Play Store but available from kingoroot.com) which will root it for you once again (it may take a couple of attempts and ensure to keep the screen awake while it works) and allow you to uninstall any bloatware from the system using App Master or a similar app.
8 - If the tablet had previously been rooted you can download the KingORoot apk (not available in the Play Store but available from kingoroot.com) which will root it for you once again (it may take a couple of attempts and ensure to keep the screen awake while it works) and allow you to uninstall any bloatware from the system using App Master or a similar app.
Further resources which may be of assistance (they were to me):
1 - XDA Developers thread: http://forum.xda-developers.com/showthread.php?t=2674459
2 - China Phone Arena on Youtube, video on using SP Flash Tools to unbrick a device like above (extremely useful to watch): https://www.youtube.com/watch?v=CVh5koB5ky4
