There has been conflicting advice in this thread if you read it all through, and i think some is inaccurate.
Superbman: First off you haven't told us what Xbox version you have. These instructions are for pre 1.6 models.
You need to connect BT to ground as in this diagram, make it exactly like this, the switch does not go here. This has the effect of always powering up the chip:
Now find where the D0 point is on your Xbox motherboard. It could be on the top or the bottom. To make the Xbox always boot from the chip, D0 must be grounded. The way is to run a wire from the D0 point to the metal plate around a screw hole. It is on this connection that your switch should go, as antz1970 said earlier. The switch should NOT go on the BT connection as you are not using that any more (it is hard wired on the chip as per the diagram above).
This is correct as stated by antz1970:
QUOTE
motherboard d0 ------------------------switch--------------------screwhole
As a final note is it really worth all the hassle so you dont have to hold the power button for a second or 2?