The Samsung GT-C3520 is a classic dual-SIM candy-bar phone with a QWERTY keypad, running a proprietary RTOS (not Android). Flashing becomes necessary when the phone is stuck on boot, shows a “download mode” loop, has forgotten security codes, or suffers from software corruption.
No. ODIN is exclusively for Samsung Android smartphones. Using it on a feature phone will not be recognized.
Your bootloader is damaged. You need to flash a full package with a preloader. Look for a “Complete Firmware Pack” containing Partition.mbn.
You also need the correct USB drivers so your PC recognizes the phone in download mode:
For most users, the free Samsung Flasher (v2.34) is sufficient. We will focus on this tool in the guide.