Hello,
For asus qualcomm devices, like just mention by Jesus , just flash csc firmware for imei repairing procedure, because csc is engineering firmware, so all diagnostic port, even root access is already open.
Before write or restore imei, please do erase imei data (modemst1, modemst2, fsg), and you can follow by writing qcn in diag port. But, again, make sure baseband version is available before writing.
If baseband unknown, even after writing csc firmware, please check hardware at first, mostly wtr ic in most qualcomm devices.
Hope this can help.
BR
madgoeslim
