Now that I have shown you there there is an Engineering Cable that can be bought to help you flash your Mi5 with a locked bootloader, what if you have no access to buy those cables?
Let me show you how to do it. homebrew style. Lets Do It!
Tools needed:
Plies
Twizer
Stranded Copper Wire
Tape
USB-C Chord
A Lot of Patience
Step 1: Fold the wire in U-Shape and make sure its parallel
Step 2: Get your USB Chord and put it in a position where the 4 gold pins inside USB is facing the ceiling
Step 3: Locate the 2ND Terminal from the Left.
Step 4: Make a little hook using the folded end of the wire and place the hook on the second terminal. make sure it does not touch the other terminals otherwise surge might happen.
Step 5: Use the twizer and make sure its aligned and touching the 2nd Terminal from the left.
Step 6: Use a small tape to tape the outside terminal of the USB Shield and make sure its thin so that you wont have a hard time plugging the USB to the USB Port.
Step 7: Now plug the USB-C to your Mi5 first and make sure its on a OFF state.
Step 8: Plug to your USB Port, use USB 2.0
Step 9: Make sure your Mi5 did not went into charging mode.
Step 10: Pull the wire off the USB port using the plies and make sure nothing is left inside, there is a chance the copper wire might break inside.
Step 11: You will hear your PC recognizing your phone. CONGRATULATIONS YOU DID IT!
Continue to this thread to finish flashing using the guide with Engineering Cable:
[MIUI DEVICE TEAM] HOW TO FLASH MI5 FROM CHINA TO GLOBAL LOCKED/UNLOCKED
http://en.miui.com/thread-299790-1-1.html
(Source: Xiaomi MIUI Official Forum)
Video Tutorial:
Here is the schematics behind this deep flasher cable we saw from @manaswb