Duox2 Gs Cromwell On 1.6b Xbox - Fragging Options

[ward78]

It's a bit of a long shot but maybe somebody can offer a solution to my problem. Basically, installing a DuoX2 GS chip into my ver.1.6b Xbox seems to have bricked it (it is now dead).

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.

This post has been edited by ward78: May 13 2011, 05:20 PM

[ward78]

I spent a couple more hours running tests on the the rebuild board and I really can't find anything wrong with it. I even managed to trace the tricky contacts back to points on the top of the motherboard to make sure that the solder joints were good connections. Everything so far has shown that the initial installation was good.

At this point in time I can only guess that it's either a faulty chip or the flashbios on bank1 just didn't work with my board. I suppose I could remove everything and attempt a rebuild just in case but I'll hang on a week or so to see if anyone has any ideas on how to proceed before I start taking stuff apart.


1) Is it feasible that a bad chip or BIOS can damage the motherboard to the point that a replacement is needed?

2) Is it possible that a bad startup can mess up the onboard BIOS or any required files on the HD that another modchip could override and/or fix?

3) In all honesty, am I just better off getting a replacement motherboard and trying a softmod?

[litspliff]

hey bud. if the board 3FRAGs without the chip (and BT not pulled), then you have done physical damage to the motherboard somewhere. often, its a surface-mount cap or resistor. dont feel like a douche. it happens to the best of us. go over the entire board. top and bottom. also look for solder balls and splashes.

can you take some pictures of the LPC as well?

[ward78]

Thanks for the reply mate, exactly what I needed to move on to the next stage.

It's been niggling me all day that the only thing I haven't been able to check are potential shorts underneath the rebuild board (perhaps some excess flux had drawn tiny amounts of solder down into the gap between motherboard and rebuild board. I don't know, maybe clutching at straws but you never know). Anyway, it sounded like the motherboard was probably goosed so I went about removing the rebuild board as a last resort, it wasn't a pretty operation!

Lo and behold, with everything removed the Xbox has started booting up with its stock BIOS.

I must have cocked up the rebuild board installation which even now I have no idea what was going wrong because it tested fine. Nor do I have an idea how it actually managed to boot up the first time with the rebuild board installed.

Regardless, I feel pretty stupid for not getting it right the first time but I'm happy that I'm back at square one and I haven't damaged the motherboard. I've been obsessing over this problem for the last 2 days so I'm going to go watch some TV now but after a nice rest I'll start again and try hooking up the header pins by the 'wire method'.

[ward78]

After the reinstalling the modchip using the wire method underneath things have been much better. The modchip is working fine and it flashed no problem.

[litspliff]

as an afternote.

all this is covered in my install tutorial in the section "I F&cked Up!" at the bottom of the tutorial.
link in signature.