Yes, there is reverse polarity protection as long as no other cables -- especially video / HDMI -- are connected to the VidiU.
If video is connected it provides a ground path and can damage components on the VidiU.
You should always confirm proper polarity on your cables prior to use, damage caused from reverse polarity power cables is not covered under warranty.
When testing a cable, power on the VidiU with just the power cable connected and no other accessory cables.
- If the VidiU powers on and starts to boot normally then the polarity should be correct.
- If the VidiU does not power on then the polarity may be incorrect, or the cable could have a separate issue.
Ideally, power cables should be assembled by a qualified technician and tested with a multimeter to confirm polarity.