Unbootable PRESTIGIO MULTIPAD 4 DIAMOND PMT7177-3G tablet diagnosis(my child device) : When power off : a) charging; b) accessing recovery menu, three ways appear on the screen: recovery mode, fast boot, normal boot. Choosing first, freeze on doing anything, choosing the other two it stuck on boot screen. When power on : a) freeze on boot screen; b) after connecting to a desktop/laptop with a various number of usb cable, freeze on boot screen and constantly connecting and disconnecting. The usb ports from desktop/laptop are ok(I’ve tried to connect the my phone in all usb ports of pc whith all usb cable that I have and everything is ok). In device manager the tablet is detected for a second, after that disappear because is connecting / disconnecting over and over again from PC. It simply can’t stay connected. I tried to disable the usb settings from power option plan, but nothing happened. My first concern is to connect the tablet to a desktop/laptop+flashing firmware. Any suggestions/tutorial on how to do it, will be highly appreciate. Tks.
Basically there's a method that works always. You need to go into recovery mode and reset the device to factory settings. How this is done varies from device to device so you have to look that up.
A warning: Doing a factory reset will wipe everything from your device.