I purchased a CnM Lifestyle Sata to USB hdd dock. All seemed well with it until one day I powered down my PC but left the dock plugged in to the USB port.
I noticed that the HDD and power light on my Computer remained on.
removing the cable from the computer turned the lights off.
A check with a Multimeter showed the cable carrying 5v even when not connected to a PC, so it was sending this back to the PC when it was unpowered.
Is this likely to harm my mainboard?