My daughter has an R7, and she is having a weird problem with the USB ports on it.
No android device can stay connected. As soon as you plug it, it makes the connect sound then the disconnect sound and keeps cycling between connecting and disconnecting.
It is not related to the device as I have tried two different phones and one tablet all with different cables, all work fine on other computers. And I tried on the three available USB ports of the laptop, all behave the same.
Searching online I found a lot of people with similar issues mostly unresolved. I did disable the USB suspend option in the power options without any results, as well as uninstall all USB hub so they would be reinstalled at boot time, and installed all optional windows updates.
She is also experiencing another issue on her USB ports, we have a Samsung slim external DVD player that uses a Y USB cable for data and power that also works fine on any other machine. On her R7, when playing a Video, the video keeps making blocks at regular intervals like something is preventing the full data stream. Wondering if this is related.
Apart from that, USB mouse, USB keys or external USB drives appear to work fine.
Anyone with a similar issue and a definitive fix?