I had exactly the same issue with a M2020. The green LED keeps ON, the blue LED on the power button ON the printer doesn't warm up and it is not recognized by the PC.
I did the next:
1) Remove power
2) Press power and the "transfer"button just above power
3) Plug power.. at this stage the printer will show orange LEDs on the power and the status indicators.
4) Go to samsung website and download the latest firmware
5) In windows go to the command console and run the firmware update.
* Unzip the firmware
* Open command console
* Go to the folder with the uzip firmware
* run usblist2.exe "NAME OF THE FIRMWARE" where "NAME OF THE FIRMWARE is the file ending with .hd
* the printer will download the latest firmware and then blink the LEDs
* Wait 1 minute
* Unplug the printer
* Plug it back