By all accounts the DuoX2 GS chip *should* be compatible with 1.6b machines so I went ahead carefully installing it following the guides that are available. As it happens the soldering job went far better than I had anticipated (especially the rebuild board) and everything was looking great. I connected the BT wire to the eject button so I could boot from the original BIOS if desired.
The first time I started the machine after installation I used the eject button and the Xbox booted fine from, I'm assuming, it's onboard BIOS as normal. Then I tried booting to the modchip and it fragged (Flashing red & green lights on console front after 3 failed start attempts). The modchip was set to bank1 by the way. Unfortunately, after the failed modchip startup it then started fragging when booting through the eject button.
I have made numerous startup attempts but it frags either way.
The really annoying thing now is that if I disconnect the chip from the header and even remove the d0 wire it still frags which I'm assuming means the onboard BIOS has been shafted. Great.
I'm pretty handy with a soldering iron and all my joints seemed fine but I started testing nonetheless. So far I've tested:
* Continuity test through all the header pins from mainboard to modchip. All great.
* Continuity tests from available motherboard contacts through to rebuild board header joints. All fine apart from 2 joints I can't physically see any contact points to test from (joints look good though).
* Voltage tests with power on. 3.3V and 5V pins were spot on through both ground pins on the header block.
* I also tested with the BT wire bridged to the header pin as recommended in some guides so the modchip is 'always on'. Still fragged.
To the best of my knowledge my soldering work is fine, no damage was done to the board and I've looked over the board surfaces for any solder splashes that may have bridged contacts. I have decent experience when it comes to soldering and electronics and it all looks great...if it wasn't for the fact that I've seemingly just bricked my Xbox i'd be sat here in a pit of :smug: at how well i'd fitted the thing.
Sadly though, I'm now sat with a dead Xbox so any help or ideas on what to try next would be greatly appreciated. It would be a shame to bin this Xbox as it's barely been used all the time Ive had it, it's like brand new.
EDIT: Oh, for what it's worth my Xbox is a UK machine with the clear cover (crystal edition?). Not entirely sure but I followed the guide on this site and it definately showed as a 1.6b version.