Suddenly, Kindle DX has lost its 3G signal.
The network signal bar just got hollow shape, even if it consisted of full bars.
Continuous reboot didn't remedy its symptom, but I found out that its time/date was reverted back to 1970/1/1.
Thought to try to factory-reset, however thankfully I bumped into this information.
r/kindle - Kindle key combos and hidden options (including browsing image files!)
Tried to visit Alt-311 and alt-611 on the setting menu, but all of a sudden it connected to 3G!
I don't know why, but try to tinker with those setting pages, when you lost your 3G on Kindle DX.
