Default sanei g706 mtkdroid tool lock when backup my rom

Hi, I have this problem when I try to backup my rom with mtkdroid tool rev. 2.5.3
It backup firmware.info mount.info mt6583android scatter.txt and phone info. After these it stops when backup preloader_and_dsp.
No error only it stops in this line for hours so I leave usb cable and mtkdroid close.

My device is Sanei g706 quad core mt8382
I have root permission root shell permissions and have recovery and busybox installed.

Sanei website is offline so i can't download my rom and I'd wanto to try to change ebr for have big primary partition but without rom backup is dangerous to do it.

Is there someone can solve my problem or have a original rom ready to be flashed with sp flash tools?

Thanks
Samsung Galaxy S3
ROM Slim Beam 6.5
Kernel:
SD SAMSUNG Class 10 32GB MicroSDHC Card