Okay, this might not be a physical install problem, per se.

I've got the LPC board put in and the header. Everything looks good. The 1.6 XBox boots fine with standard BIOS by pressing eject, but booting from the DuoX2GS BIOS gives a blank screen in Bank 0, in Bank 1 it gives a blank screen again, but I hear the DVD drive trying to work. It whirrs a couple times then quits. The eject button light comes to a solid green while the light on the DuoX2GS blinks red.

Is this the "fragging" I keep hearing about, or is the matter that flashbios does not work with some 1.6 motherboards? The 1.6 in question is a Canadian Crystal Edition box if that helps identify a problem board.

Edit: Well I guess it must be fragging. I must not have noticed this before but the red LED is flashing even in Bank 0. Grr.

The duo should blink red. Double check your soldering work and make sure you have no bad connections or shorts. The flashbios bank can give blank screen on version 1.6b boxes, but Cromwell should boot ok ready for flashing.

All right, going to go over it again. I take it that when it's functioning properly it shouldn't blink red though?

By the LPC board I assume you mean the LPC rebuild board for 1.6 xboxs. I would also make sure that is installed correctly as well.

Yes that is what I mean. Unfortunately I can't see how it might not be connected... I followed spliff's howto here and it seemed simple enough... I can only gather that the LPC board must not be making good contact with the motherboard somehow though. Ugh. I tried to be precise and use as little solder as possible so as to not make a mess. When I went over it again I spotted a couple of header joints that could have used a little more solder, I also reflowed the points joining the LPC and motherboard but still no go. Is anybody good with this kind of repair?? I don't see anyone offering installs in the BST forum, and I'm a little afraid if I go pulling this apart of really screwing up and breaking something.

I might be able to help you repair it, but I'm sure we can get this figured out. Does it boot into the stock bios if you take the modchip off the LPC pin header? When you boot it in either bank 0 or 1 does it give the christmas light frag? Or does it just blink red? What does the modchip do? During normal operation it should blink red at a steady pace.

Really... well, it blinks red at a steady pace, from either bank. That's it. The only green light going on is the one around the eject button. It blinks a few times after I first press power, I hear the DVD drive whirr, the DuoGX2 blinks red. After the drive quiets down the eject light is solid green, and the DuoGX2 GS LED continues to blink red. I have no video from the XBox on the TV, no sound either, no throbber going on, just nothing.

Okay I just tried it again with the chip unplugged completely, the XBox boots and all seems well. So... what could my problem be? I don't guess it's possible my chip has no BIOS on it at all??

might be that cromwell does not like that motherboard. If you have a friend or some one who you will let you try that chip in there xbox and then maybe flash it with a 1.6 bios that might be your only option.

who knows?