Lumia 520 Black Screen

Hy

I try to flash my Lumia 520 with black scree ( I think is in recovery mode ) but ATF always give me this error:

Windows Phone 8/8.1/10 Lumia Flasher
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If the Phone is ALIVE
1. Power On the Phone and Connect it to the USB Port

If the Phone is DEAD
1. Connect Phone to the USB Port
2. Press and Hold the VOLUME DOWN and POWER Buttons
3. Wait until the Phone Vibrates Shortly…
4. Stop Pressing the Buttons…

If the Phone is DEAD BOOT
1. Connect Phone to the USB Port
2. Install Correct Drivers:
"Nokia Emergency Connectivity" Located at:

C:\AdvanceBox Turbo Flasher\Driver\NOKIA_X2_USB_DRIVERS\
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Recovery Handle Found! – (Qualcomm)
ERROR: Cannot Open COM PORT
ERROR: Flashing Failed!

Any help here how to flash correctly this phone?

Thanks in advance

B.R.