xbox 1.6 considerations
When working with version 1.6 motherboard's there are a few things to watch out for. First of all is which version case you are installing the board in. If you are installing the 1.6 board in a 1.0 - 1.5 case you will need to remove a extra stand off that the 1.6 does not have. Failure to do so will result in the Xbox not powering on anymore without the applying fix explained below.
Locate this stand off on the bottom of the 1.0 - 1.5 case and remove the tin ground tab by bending it back and fourth until it shears off. This is most important because it will ground out with your board and cause the problem described below.
For best fit, use a cutting tool of some sort to slice off a small amount off the top of the video connector stand off's. This height has changed between versions and will warp your board and potentially crack your avip connector if you don't trim them.
Second you should always make sure that you do NOT have your A/C power cord plugged into your Xbox when you plug or un-plug your motherboards ATX connector. It is a sure way to blow the transistor shown below resulting in a Xbox that will not power on.
1.6 Xbox will not power on fix
I found this to be the case after working on a failed mod board. I was in the process of repairing traces and booted it many times without issue then suddenly without warning the box would suddenly not respond to power or eject buttons. I remembered reading an article by the guys at www.teamxodus.com titled "Resurrecting a damaged V1.6 Motherboard "
I found the collector to be producing unstable voltage of less than 3v. This confirmed the issue the board was having, I purchased some of the MMBT3906LT1 transistors (available here) and found replacing it resolved the power on issue.
To install I found a good set of tweezers essential for positioning it. For installation and an x-acto knife easies removal. With the tip of Gently pry up on the single conductor side, heat the side with the single conductor and bend it upwards then repeat on the other side with the dual contacts. Installing was fairly easy as well once it is properly positioned, solder the single contact at a low temperature and continue on to the side with dual contacts once positioned properly.
