Echo Grounding Notes

[electronrancher]

Just a note that you should be careful with grounds. I use an echo with a mini HD projector sometimes, and I found that if the echo's USB power block is on a different power strip than the projector's AC->DC adapter the device will suffer lots of restarts and hiccups on initial power up. If it can get going it's usually good but sometimes a high-power event like starting a movie will still cause an unexpected restart.

This can SOMETIMES be cured by putting both the echo and the projector on the same power strip, but there are still occasional issues. If I run the projector from battery, there are no problems.

So if you find yourself with weird restarts or unreliable startup, double check ground on the echo and your display. Sadly, many displays (and the echo) use a 2-prong outlet - this can give different ground voltages on USB and HDMI, which causes current to flow in the USB/HDMI shields, which ends up glitching the chips and causing the weird hiccups and restarts. I've seen this a lot of times on microcontroller boards with PC USB and AC wall warts, and wanted to mention for those users who complained about these very kinds of unexpected restarts.

[mcewinter]

Otherwise known as a ground loop. Plugging one system into more than one circuit can cause this to no fault of the echo.

It can also be a sign that the wiring in your home may not be correct. Plugging into one circuit is the obvious and best solution but a little research and thought should be applied when attempting to troubleshoot.