Ground loop causing electrical sparks and equipment damage when connecting powered camera to sled-mounted electronics via HD-SDI cable

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2013Batteries/Power forum

13 years old. Gear and prices may have changed since.

Connecting an already-powered camera to a sled with separately powered electronics via HD-SDI cable can create a ground loop if the camera chassis and sled chassis have different electrical potentials, causing sparks and component damage.
The issue occurs specifically when the camera is powered on before making the final HD-SDI connection; establishing all connections before powering equipment or powering down the camera before connection can prevent ground loop formation.
When multiple independent power sources exist in a system with shared chassis grounding, electrical current may flow through video connectors instead of intended paths, causing damage to converters and other connected electronics.
A camera chassis should not normally have electrical charge present; if sparking occurs when connecting a camera to external equipment, the camera battery plate or internal grounding may be at fault rather than the receiving device.

The exact root cause was never definitively confirmed with testing equipment; the diagnosis was based on elimination and expert hypothesis rather than voltage meter measurements.
Ground loop theory was proposed but the user could not perform full verification with proper test equipment at the time.
A related incident was reported by another user with a RED camera v-mount plate, but whether this represents the same underlying issue was not conclusively determined.
The camera involved was not owned by the person experiencing the problem, limiting ability to inspect and test the camera itself.