Spróbuj tych instrukcji:
(cały długi tutorial z róznymi opcjami jest tu - https://forum.xda-developers.com/le-2/help/bricked-le-s3-x626-flashing-twrp-power-t3715937
Part 2.1 Installing the MediaTek drivers
First you need to get Windows into unsigned mode. The instruction below is fairly straightforward and taken from Dell website.
1. Click the Start menu and select Settings.
2. Click Update and Security.
3. Click on Recovery.
4. Click Restart now under Advanced Startup.
5. Click Troubleshoot.
6. Click Advanced options.
7. Click Startup Settings.
8. Click on Restart.
9. On the Startup Settings screen press 7 or F7 to disable driver signature enforcement.
Once you've disabled signed driver enforcement, you can try to restore the drivers - so here are the next steps:
10) If you haven't done so, go to device manager and connect the x626 to the PC's USB
11) Sometimes, you have to wait for a minute or two for the PC to recognize the phone. If this doesn't work, unplug, try holding the power button and Vol - for 15 seconds then let go, it 'wakes' up the phone somehow, then connect it back in. You might need to do this a few times.
12) If you get it to work, it will try to install a generic USB driver. Wait for the generic USB driver to show up under "Ports (COM & LPT)" (along with the USB connect chime sound), then click on "update driver"
13) Select "browse my computer for driver software"
14) Select "Let me pick from a list of available drivers on my computer"
15) Select "Have Disk..."
16) Select "Browse", then find the Windows+10_MTK+VCOM+USB+Preloader+Drivers inf file that you saved earlier and click on the appropriate version (x64 for me)
17) Now you will have the option to replace the generic driver with the new drivers. I personally selected "MediaTek DA USB VCOM" driver.
Note that luckyrai had success with the preloader driver instead of the DA USB VCOM driver. So you could try those drivers instead if you're stuck later on
Part 2.2 fixing USB connect and disconnect
This was the most difficult part for me (and I guess a lot of people) - but here's how I resolved it:
Note that both luckyrai and blueasteroid stated that steps 1-5 below is not be necessary in their experience
1) After the MTK driver installation is completed, take out the phone
2) Keeping the device manager windows opened, plug the phone back in again
3) After this, disconnect the x626 from the PC's USB port and reconnect again. The PC will most likely try to switch to another COM Port and reinstall another generic USB driver. If it does that, repeat step 5 and overwrite the new generic driver and COM port with the MediaTek DA USB VCOM driver . Keep doing this until you end up with a situation where you have the PC cycling between 2-3 COM ports in the connect/disconnect loop but at least they will be showing MediaTek DA USB VCOM every time.
4) Now reassign all these COM ports (right click, properties, Port setting, advanced) to a single designated port (like, say "3").
5) If you follow this instruction, the phone will still connect and disconnect from the USB, but each time it does so the phone will always connect to the same COM port and using the same driver - this will make it easier to flash though success is not guaranteed every time