Reinstall the Nokia USB drivers and try a different USB port (preferably on the back of the PC if using a desktop).
Ensure the phone has at least 50% charge to prevent it from dying during the process, which can permanently brick the device. nokia asha 501 rm 902 flash file download
The RM-902 flash file is a specific firmware image designed for the Nokia Asha 501. The "RM" prefix refers to the device's model number, which is used to identify specific firmware versions. The RM-902 flash file contains the software components necessary to restore or update the Asha 501's operating system, including the Series 40 UI, to a specific version. Reinstall the Nokia USB drivers and try a
Power off your phone and connect it to your PC via USB. If the phone is recognized, select PC Suite or OVI Suite on the phone screen. The "RM" prefix refers to the device's model