i have tried different charges and usb cables but still same story.
if tablet i not in sleeping mode it charges ok.
the problem is when after 30 minutes, when going into sleeping mode
The charging current should be 1.7 Amps. The easy way is turn off your tablet when charging, check percentage by pressing the HOME button, the green flashing battery icon should show up.
This is the first step you should do to verify your tablet is charging normally.