huawei y520-u22 error connecting

Using library Brom_DLL_v7.1413.5
Searching phone in normal mode;
[connect the phone powered off to the usb cable]
Phone detected (MediaTek PreLoader USB VCOM (Android) (COM5))
Preparing to start flash mode;
Preparing to open COM5
Connecting;
Downloading DA;
Initializing;
ERROR: Connection failed ! If error persists try other connection mode;
ERROR: BOOT_PHONE;

with all connection mode same problem
help plz