Hello,
I began having issues with my Lapbook 15.6 Cherry Trail (slow af on regular Windows but has become a sweet retro gaming pc thanks to Atlas OS, which clears out all the bloat, try it) a while back. I tried to install Windows but the screen would just flash when trying to start from the install usb. I tried both uefi and mbr setup media but the same thing happened either way. I also would other operating system installation usb’s did the same thing. I did lots of troubleshooting, some making things better, some worse (at one point I lost the ability to boot the installed ubuntu os too.)
Eventually, I found that the BIOS option reset system with ME (Intel Management Engine) disabled would allow the system to boot normally, both from internal storage and USB. This made me realize that something must have gone wrong with the ME ( it existing at all is wrong, but that’s a different subject) and I began looking for things related to it to disable to perhaps circumvent the problem. I had already disabled TPM and secure boot but I had missed one part; the fTPM, which I learned is a software version of TPM. Turning that off and saving and resetting seems to have solved the issue completely, as the device now boots right up every time and also boots from installation USB’s.
So the TLDR is if your chuwi lapbook or similar device is no longer booting, try turning off fTPM. Disable other possible offenders too, like TPM and secure boot.
I also managed to solve the problem with no audio when running Linux on it, if anyone’s interested.