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My Samsung Tab A SM-T580is dead. Hasn’t been used for months because it was packed away. I looked at messages on how to solve the problem. I held down the power button at the same time as the volume up bottom for 30 seconds, released the power button and plugged in the USB cable. After 30 seconds, I released the volume up button. I then received the above message with a blinking charge button. Don’t know what to do next. Please help. Thanks.
Tablet is most likely running custom software and will need to be re-flashed back to stock original software that came with the device. I would leave this to a reputable phone / tablet repair store to get this fixed. They will need to re-flash the Samsung Firmware on the tablet and most likely it will also need a factory reset afterwards.