Mediatek flash tool device in device manager disconnects I am trying to flash a rom via mediatek flash tool, my problem is that when I connect the tablet to my PC it connects the mediatek preloader but after 2 seconds it disconnects. What can I do with this ?
Flash Stock Roms with SP Flash Tool

Step 1: 
Download and install Android USB Drivers on your PC. Skip this step, In case the drivers are already installed.

Step 2: Power Off your MTK Device.

Step 3 Download the suitable Firmware for your device, and extract it on your PC.

Step 4: Download and Extract SP Flash Tool on Your PC.

Step 5: In the extracted folder, launch Flash_tool.exe

Step 6: Click on the Download Tab.

Step 7: In the Download Tab, now click on the Scatter-Loading button.

Step 8: Navigate in your Firmware Folder and select Scatter File (A txt file ending with scatter.txt).

Step 9: Click on the Download Button to launch the download procedure.

Step 10: Connect your device to the PC using the USB Cable. Your device should be Powered-off.

Step 11: Once Flashing is completed, a Green circle dialog appears, now you can disconnect your device from the USB Cable and Power it on to check whether it's ok or not.

P.S: Don't select Preloader while flashing unknown Firmwares.