Connect the SATA cable from the Xbox 360 to your PC / SATA card
and then turn on the PC and boot from the USB flash drive into DOS.
The Xbox 360 should still be off at this point!
Type in the following command, using your 4 digit port that you got
DosFlash 1.3 use:
DosFlash e xxxx 1 a0 1 4 D8 0
DosFlash 1.4 use:
DosFlash e xxxx 1 a0 1 4 C7 0
Note the spaces, they are very important. Put a space wherever you
see an underscore below. DO NOT type the underscores in DOS,
they are just for your reference here and to make the spaces easier
to see.
DosFlash_e_xxxx_1_a0_1_4_D8_0
or
DosFlash_e_xxxx_1_a0_1_4_C7_0
[press enter]
DosFlash16 will ask you if you want to resend the MTK Vendor Intro
command, enter Y for Yes. When you hit enter the drive status is
shown on the screen, it's something like 0x7F, this will change during
the next few steps.
Turn on the Xbox 360 and wait 2 or more seconds, status toggles
between 0x51 and 0xD1.
Turn off the Xbox 360 and wait 2 or more seconds, status will stay at
0xD1.
Turn on the Xbox 360, you should get a good drive status 0x73 and
erasing should begin automatically
After that you are good to flash
Also check this link.
Philips/BenQ/LiteOn VAD6038 Tutorial