Hi.
I'm currently trying this out.

My first N9 died a week ago and couldn't charge it anymore. Reading the posts here I decided to buy a new battery, but the thing didn't work either......maybe it's wishful thinking but there may be another internal battery inside the device apart from the main one, and it is discharged?

Fortunately I happen to have a USB controlled USB switch and now I'm powering it on and off in duty cycles with 26 seconds on and 4 seconds off.

Let's see what happens.

Regards.

PS: The USB device is this.