I tried to do a BIOS update from Windows. Flashing finished without an error so I decided to reboot. The tablet shut down and… never turned on again. Nothing of what I tried had any effect, the tablet remained dead. Not A sign of life. So I decided the BIOS flash must have gone wrong. What now?
After some research I found that there were more people with the same problem, and some seemed to have successfully flashed their BIOS again. So I decided to give it a try.
First of all I needed some hardware. I searched online for a BIOS programmer, and found a cheap CH314A programmer that should do the job. It had TTL and 3.3V levels, I knew that the BIOS chip was 3.3V so it should work without frying my BIOS chip.
Next step was to find a way to program the chip without soldering. I knew that the chip was in SOP8 package, so I searched a test adapter for a SOP8 chip, and ordered one.
After about a week the hardware was in, and I could get to work. I found the correct BIOS and found a bin file in the download. Then I installed flashrom and connected all the hardware together.
First I made a backup of the current rom using flashrom:
flashrom -p ch341a_spi --read backup.bin
After this, I disconnected the test adapter, disconnected the battery, reconnected the battery and tried to boot. And with success, the tablet booted straight up to Windows!