Arduino Uno 13 pin diode is still on and can't upload nothing

Hi, i just get absolutly new arduino clone named DCcuino with CH340G(USB to serial) and (of course) ATmega 328P from eBay (http://www.ebay.com/itm/121553610522).

There is few problems.

1, "L" LED (13pin) is still turned on!
It flashing from first powerup until now. When i connect my own LED with resistor it not even light up and SMD diode turned off.

2, I can't upload any sketch
I reinstalled drivers many times from many sources and still getting various error messeges like:
"stk500_getsync() resp=0x**" There is different hexadecimal number every time ("**")

When i tried to do loopback test, nothing appears. TX/RX diodes never blinks. Only ON and "L" diode still lights on.

I'am so sorry for my sometimes bad english, and i hope you will help me with it.

Thank you so much.

Mattew