A példa a Chuwi Hi12 bios helyreállításáról szól, de felhasználható minden tipusnál, a Chuwi tableteknél.
BIOS corruption occurs when something goes wrong during a firmware update process. Either the wrong BIOS file was flashed or the process got interrupted by usb stick removed or tablet powered off too soon. When this happens the tablet will not be able to turn on anymore so you cannot re-flash the BIOS by the usual means – instead you will need to open the tablet and flash the BIOS using an external usb programmer connected to another computer.
The BIOS chip in the Hi12 is a Winbond W25Q64FW. It is a 1.8v chip and most cheap programmers are 3.3v so you will need a 1.8v adapter.
To open the Tablet, first remove any microsd card or plugs.
Remove the four corner Torx T3 screws and place in a container for safe keeping.
Using a guitar pick or similar pry tool work your way around the edge of the metal back cover to gently pry it away from the screen edge.
After removing the back, peel back the black tape covering the wire from the battery so you can unsolder the red positive wire. Wrap the end with a bit of tape to prevent accidental shorts.
The BIOS chip is hidden under the CPU thermal pad. I cut away the corner of the pad but you will also need to hinge open the metal cover.
Before connecting the Test Clip you will need to get the software working on another computer. You will need at least version 1.29 of the CH341a software that has support for the W25Q64FW chip as posted by Richard in this thread:
But first you will need the driver. I used the one in the flash package posted by Chris in these links:
Plug the CH341 into your computer. Unzip the flash packet posted by Chris but don’t install ver 1.18 as it’s too old. Open the Treiber folder (I think German for driver) and run the driver setup:
I used an old computer as it’s not a signed driver and will have trouble with Windows later than win 7. Someone may know a link to an updated driver. Accept the warning:
Then install the version 1.29 software you downloaded separately.
I still got a warning about the driver when I opened the software but I clicked OK and it worked.
Make sure the correct chip is selected as shown.
I would now unplug the usb while you attach the Test Clip to the BIOS chip making sure the red wire is positioned at pin 1 indicated by dot on chip.
The same with EZP 2010 programmer:
- Detect Chip
- load bios.bin
- If verify chip ok.