Originally Posted by SkyDream
As a last resort you can try to remove the battery. Remove back and use the shipped screwdriver to remove the battery. This should power off the device.
Thank you for the piece of advice...
Finally, I removed the battery... I was expecting the screen going blank when I took out the battery... then I remeber that it is electronic ink-
... It worked... Nevertheless, I'll keep the screwdriver close...
By the way, do you know where can I find a decent PB903 manual in English?