This points to a hardware/electronics fault, not a settings issue. Because the corruption appears on both the LCD preview and the saved files, the problem is likely in the image sensor readout path or the camera’s main/logic board rather than just the screen.

The vertical striping, Dust Delete Data failure, and Err 70 all fit an intermittent internal connection or failing component. A common explanation is a bad solder joint, ribbon/bus connection, or other board-level fault that temporarily works again as the camera warms up or after power cycling.

If it has recovered for now, that suggests an intermittent fault rather than a one-time software glitch. Unfortunately there’s usually no reliable user fix beyond basic checks like reseating the battery/card and observing whether temperature, movement, or time affects it. If the issue returns, it will likely become more frequent or eventually permanent.

Practical advice: back up images promptly, test the camera regularly, and plan for professional service or replacement if it recurs.