USB Connection problems

Hi Guys,
I have yesterday recived my APM 2.5.
All drivers are installed correctly.
After connecting USB cable (original) to APM… nothing happend. APM was off.
I have connected to battery and it turned up. But still green LED wasn’t glowing.
Conntection with MissionPlaner was impossible, only in terminal something showed up

But still, it wasn’t working without battery.
I changed a USB cable, and it worked, so I thought.
APM turned up without battery, but one’s again there’s no green LED glowing.
Only yellow and red(GPS), red and blue are blinking. Still connection with APM is impossible.
Windows correctly recognise the APM, but there’s a problem with connection.
Is it possible, that it’s something wrong with my APM ?



Here is a link to the meaning of the APM leds:

Unless your power led is defective, it should show up as a dull green color through the case. In sun light or a bright room it is hard to see that it is on. Since you can see the other leds, the board is obviously receiving +5vdc from the USB cable.

When you have the USB cable connected, have you selected the correct Com port and baud rate in the upper right hand corner (next to the two plug symbol) in the MP? The Com port number will usually have the device identified after the Com number, ie Arduino 2560. Also the Com port should be set to 115,000 baud.