GT-E2121B Cannot connect to the samsung tool for unlockin

hi,
I tried to unlock Samsung gt-e2121b with z3x box. I am using cable E210.
I connected the usb to the z3x box, selected right port on samsung tool, tried both options flash mode and tat mode.
tried to connect phone with battery and without it.
tried with sim and without it
tried read codes and direct unlock, but it fails all the time.

Error in TAT:
Operation: Read Codes
Selected model: GT-E2121B
Selected port: COM91 USB Serial Device, 115200
Software version: 34.8

Connect phone and press power button... Timeout




Error in flash:
Operation: Read Codes
Selected model: GT-E2121B
Selected port: COM91 USB Serial Device, 460800
Software version: 34.8

Connect phone, press power button
Waiting phone... OK
Sending PRELOADER... error (2)


Please can someone explain the process of unlocking? This is my first time using z3x and it is not explained well.