caligirl,
If power is cycled quickly & repeatedly, some electronics can get into a locked-up state, for any number of reasons unfortunately.
While powering up, there may be some reading/writing to a disk or flash memory. Incomplete writes could occur.
While powering down, the device may be storing status and various states of operational items (so as to "restore" those items upon powerup), and if the device is then told to power up, and shortly after, power is removed, the device can get confused.
I only have general knowledge in this area.
But Consider:
- Some devices include rebooting instructions such as "remove power, wait 15 seconds, then restore power".
- Connecting DC power to a device that has its power switch set to "'ON" is not "Best Practice". Inserting the DC connector does not always result in a nice, clean rise in voltage from 0 to 12v (or 5V, 24V, whatever) A so-called "step waveform". Especially if the connector has oxidation. What the device sees is many up and downs in voltage over a short period of time, and then eventually settles down to a steady voltage. See pic of a power-up waveform.
"Best Practice" is to connect power only when the device powere switch is OFF. After power is connected, then turn the device ON.
But it sounds like you and looney2ns may have figured out the problem.....
Fastb