This topic covers both Original and SE versions.
When using certain USB power sources to power SKULPT, such as USB wall chargers or USB battery packs, you may find that moving the power switch to OFF won't turn off the unit and will instead produce erratic noise. Moving the power switch back to USB will then cause the SKULPT to not function correctly.
There are several solutions to this:
- Physically disconnect the USB cable from the SKULPT when powering off the unit
- Use a USB power source that doesn't have auto-sensing (such as the USB port of a computer)
- Use a simple power-only USB cable or adapter such as the Kenable Power-Only Extension Cable: https://www.amazon.co.uk/kenable-Power-Charging-Cable-Extension/dp/B005HRSI3C/. Please note that 'smart' USB data blockers (such as https://www.amazon.co.uk/dp/B00QRRZ2QM/) will not work for this purpose.
To explain why this may occur - USB power sources that are designed for charging (such as USB wall chargers or USB battery packs) send a power/charging signal through the USB data wires to charge devices at high speed. Also, some USB power adapters and battery packs try to conserve energy by switching off when not in use, so to enable them to spring instantly to life when something is connected they send power signals into the USB data wires. Therefore for the SKULPT, even though the power is switched to OFF, the charger/battery bank may continue to supply power into parts of the SKULPT circuitry