Trapped in fastboot mode with locked bootloader and corrupted custom ROM

[rar0]

It seems @k4y0z got the EDL loader from the Xiaomi Redmi 7 firmware package:

Fairphone 3 unbricking

Originally I assumed we would need a programmer that is signed by Fairphone/Arima. But since they didn’t burn in the PK HASH fuse, and therefore aren’t checking sbl1/programmer signatures any compatible programmer should work. Since Xiaomi publishes their programmers and the Redmi 7 shares the same platform I found it in the Redmi 7 firmware package: https://bigota.d.miui.com/V11.0.2.0.PFLMIXM/onclite_global_images_V11.0.2.0.PFLMIXM_20191022.0000.00_9.0_global_b0cd3cab92.tgz Did you try to…

I tried the EDL loader from the Xiaomi Mi 10T Lite which also has a Qualcomm Snapdragon 750G but also got the signature error. The EDL loader for the FP4 is signed, so loaders for other smartphones won’t work as on the FP3.