I had an issue after software upgrade my B315s-936 refused to boot and stayed with only the power light on. The following sites and firmware helped. It is now working 100%
I had to make my own USB A male to male cable, but it's very easy, it's a one to one connection +V to +V, -V to -V, +D to +D...
I assume you've gone through the process of upgrading the firmware. I had an issue after software upgrade my B315s-936 refused to boot and stayed with only the power light on. The following sites and firmware helped. It does have a USSD tab after upgrade
B315s 936 Huawei RELOADED 2023 Firmware...