Hi Ravi Ch,
I think that the problem is solved. I successfully charged my laptop, all LED's were off after a couple of hours.
I don't know if it's just a coincidence or what, but I unplugged Logitech Unifying Receiver from USB port(which I use for wireless mouse). Before problems with charging, the Receiver was plugged to eSATA/USB port, but I think that the problems with charging began when it was plugged to just USB port. I accidentaly plugged it to that port (which support charging while laptop is power off, correct me if I'm wrong). So maybe that was the cause of the problem.
Now I have a problem just with one little thing: I changed to Dell Power plan, but after every restart Windows automatically change it to Power saver plan, so I have to manually change it to Dell power plan. Any way to set Dell Power plan as a default plan on startup?
Thank you for your reply and help.