Default PROBLEM: DOWNLOAD MODE SAMSUNG S3-i9300

okay.. i tried everythinng.. i cant get into DOWNLOAD MODE of this Samsung Phone.. when i tried to Press POWER+HOME+VOLDOWN it boot in STOCK RECOVERY only or this Android System Utility (3e) orange color..

Model Number: GT-I9300
Android Version: 4.2.1
Baseband Version: MAUI 11 AMD.W12.22.SP.V17, 2013/3/07
Kernel Version 3.0.131212V72
BUild Number: IMM76D.GT-HI9300ZSALE9
Custom Build VErsion: 1387788918

is there anyone who can help? because i want to flash my phone to its original firmware..
thanks XDA advance..