I don't know, to be honest with you. Try both. Leave it charging overnight both on and off the phone, etc. Keep finding with the buttons, trying to reset the device.
Also, I'll post later about the USB permissions.
---------- Post added at 08:24 AM ---------- Previous post was at 07:52 AM ----------
Re: USB device permissions.
When you attach the cam plus, as you already know, the Friends app tells you to authorize the app to use the USB port. Now, what I found one day was that a notification actually popped up on the screen of the G5, asking me to authorize that very thing. I tapped on Authorize and the rest is history; it started charging, I was able to use it from then on.
However, when I plugged one of my other cam plus modules into the same phone, I was back to square one. The "enabled" cam plus works okay now, except that when it's attached, sometimes the g5 thinks (because it's a USB device) that I'm trying to transfer data from another phone, and it pops up a screen telling me how to move that process along. I dismiss that screen, and then I can use the buttons on the cam plus. This can get frustrating because on a bad day, that damn data transfer prompt shows up every time I unlock the phone, and I have to dismiss it every time before I can use the buttons on the cam plus.
That's just given me an idea, actually. Start the LG app for data transfer, or backup, after you attach the cam plus. It might toggle something to make the USB permissions dialog come up and you can then enable the cam plus.
When I get home I'll try this with one of my non functioning cam plus modules and let you know how I get on.