Hello, I hope someone may have an answer for me, I have a rebel T3 and I would like to connect it to my computer and a power adaptor at the same time, to do so I have connected the USB to the computer and have the ACK-10 power adaptor in place of my battery. When the adaptor is connected my camera works fine and is powered up, however when I plug in the USB to my computer the camera acts like it has a loose connection and powers on and off with the computer connection sound connecting and disconnecting over and over until it just stops and does nothing until I disconnect the usb cable and it works fine again. On the other end of the scale It also works fine on the computer if I have the Battery in use instead of the adaptor. I have turned off the auto power in the camera menu to try to fix it but to no avail. Any ideas? Thanks in advance.
What you are describing are classic symptoms of a ground loop. The fault lies with either the USB port on the computer, or the power adapter. Are using all Canon gear for the power adapter?
If you are using a laptop, then unplug its power adapter.
A ground loop seems unlikely as such a thing as far as I understand pertains mostly to acoustic and sound devices. But... I reversed the plug, I tried different sockets and grounded space bars. So i ordered and recieved another power cord with a USB plug instead of a socket, to no avail, same issue...then I thought perhaps the usb to the computer was powering and/or charging the battery so I put the regular battery back in but nope...the battery died. I am at a loss.