Chuwi Hi8 BIOS Flashing – what to do when USB OTG is not working and Windows 10 won’t boot

The BIOS and BIOS configuration are stored in non-volatile memory (a Flash memory chip).  If you badly configure the BIOS, like I did, you can lock out access to USB and even stop the tablet from booting.

(If you are able to launch Windows it is possible to flash a new BIOS with a Windows utility – search the Chuwi support forum for details.)

If you can’t boot in to Windows then you have to use these flashing tools…

You will need:

  • A soldering iron – to disconnect the battery from the circuit board.
  • Flash Memory Programmer interface (CH341A with 1.8V adapter and in-circuit clip)
  • CH341A Flash Programming software – CH341A Flash Programmer V1.30
  • Chuwi Hi8 BIOS image – download the latest from the official Chuwi website or Chuwi Hi8 BIOS 207.
  • A Torx #3 screwdriver to open the Hi8 case. (Then use a credit card to unclip the back of the case from the front.)
  • A PC to run the flash programmer

Before you  program the BIOS you must unsolder the red wire of the battery. Its a good idea to wrap the end in some tape to prevent accidental short circuits.

Lift the metal shield by the edge using a fine blade being careful not to damage any of the very small components. The metal shield is held in place by clips.

Pin 1 of the BIOS chip is not the one marked with green. The PCB has an arrow and the chip has a black spot for pin 1:

The red wire of the in-circuit programming clip connects to pin 1.

After this preparation you then:

  1. Install programming software
  2. Connect up the flash programmer
  3. Connect in-circuit clip to the BIOS chip (Red wire to pin 1)
  4. Click the programmer detect button to auto-detect the chip
  5. Make a backup of your chip’s BIOS. Read the BIOS image from the chip and save it to you hard drive.
  6. (If you cant do step 5 do not continue further!!!)
  7. Erase the BIOS from the chip
  8. Load the new BIOS in to the flash programmer
  9. Write the BIOS to the chip – make sure it verifies correctly. Repeat if necessary.
  10. Remove the in-circuit programming clip
  11. Close the metal shield – make sure it is aligned with all the little clips.
  12. Solder the battery red wire back on to the board.
  13. Power up the tablet to make sure its working. Power it down.
  14. Close up the case

Now the BIOS is back to default settings and you should be able to use USB OTG again.