Another purchase — SanDisk Ultra 64 GB microSD UHS-I card for our Galaxy Tab 3 8.0″. It is UHS-I — one class above Class 10 cards. However, as you can see, not all Android device controllers can read/write at the full speed.
Download your ROM and LiveSuit (for me it is Q76, but there are ROMs for all models, like Q71, Q75, Q81, Q91, etc.);
Do not install anything! You will install USB driver only when Windows asks;
Start LiveSuit.exe program;
Select ROM by using SelectImg button;
Plug USB into PC (do not plug into tablet yet, this is important);
Press and hold Volume Down button (Symbol “-“);
Plug cable into tablet (while keep holding volume down);
Press Power on button several times. Some says 5 or 10, but I kept pushing till Windows made the USB plug sound. After that sound I release Volume button, and stopped clicking Power button;
If there are no USB sound, and nothing appears on the PC screen, then unplug the cable, and start from the step 7. In the beginning it was not working for me. May be need to push Power a little bit faster or slower, but keep trying;
At this point Windows asks for USB driver. Point it to the USB folder in the LiveSuit folder. In consequent tries it will not ask this;
Important thing is, that nothing appears on the tablet screen. It seems like something is wrong, but everything is OK. On tablets from another manufacturers, there is usually some Androidicon, and some info, but not for this tab;
After short period window with Yes/No appears on the PC screen (see the screenshots below). “Yes” — updates ROM with full wipe, and “No” — updates without wipe. I clicked — Yes. To cancel, unplug tablet and hold Power button several long times (more than 10 seconds);
Wait for ROM being uploaded to the device;
Device should reboot automatically, and come up with updated/refreshed/reset firmware.
Again, USE THIS INSTRUCTION AT YOUR OWN RISK. If you accidentally have bricked your device, do not panic. Try do download the Firmware again. Double check, that it is for your device. And try all flashing process again. If that does not help, you can try to ask for help in the xda-developers forum.
Some say they succeeded by holding Volume Up (“+”), but it did not work for me.