Softbricked a Galaxy S3 Virgin phone. Help? topic

I guess i goofed and got softbricked. here is the Odin log.
I used the video on the xda-developers youtube channel, but i cant post a link on the thread due to the 10 post rule.

<ID:0/003> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> root66_BMC_I747MVLUEMK5.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/003> Odin v.3 engine (ID:3)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> sbl2.mbn
<ID:0/003> NAND Write Start!!
<ID:0/003> sbl3.mbn
<ID:0/003> aboot.mbn
<ID:0/003> FAIL! (Auth)
<OSM> All threads completed. (succeed 0 / failed 1)

Any way to fix this? Id like to continue with the root, however if absolutely necessary ill go back to stock provided anyone knows where to get it.