Groups like "Atoto Car Stereo Enthusiasts" often have pinned posts with Google Drive links to repacked "rescue" firmwares. These are usually tested by admin.
Atoto maintains a legacy firmware archive at support.atoto.com/pages/firmware . However, as of 2025, most links redirect to the F7 XE only. For older F7 units, you need the archive. Atoto F7 Firmware Download REPACK