I replaced my bottom module, booted my FP2, unlocked it and connected it with my Win 10 PC via USB. I had a stable connection - but only one time. After that each attempt to connect both devices failed. The windows device manager says: Unknown USB device (error when requesting a device description).
I booted FP2 in fastboot mode. The windows device manager shows an unknown Android device. I installed a driver, using the downloaded Google USB drivers. Windows recognizes an Android device. I have a stable connection. I can reinstall the FP operation system (https://support.fairphone.com/hc/en-us/articles/360042185512-FP2-Manually-update-with-Windows). When I shutdown from fastboot mode and boot the FP2, everything works fine. But I cannot connect the phone via USB to the PC.
My cable is working, the USB port works in the fastboot mode, but not in the normal mode. When I install my old bottom module (with broken microphone), the USB connection works.
The new module is from Switzerland, whereas I live in Germany. Are there any local restrictions?
I am using the fp2-A9-gms-21.12.0-rel.1 and Windows 10 Pro. USB debugging it enabled. The Android Debug Bridge (ADB) is installed.
I took a look into the FP2 settings. The standard for USB connection was already “File transfer”. I did not change it. After that I connected the FP2 to the PC again. Suddenly a dialog opened and told me that MTP is going to be installed. Now I have access to the phone. In the device manager I see an USB device called ADB interface.
I really don’t know how this problem was solved. Just by opening the settings?