XD Card Mod Questions [Slim]

[gy-repairs]

I have been through numerous posts on the forum regarding the XD card mod on a slim but needless to say details are a bit sketchy. Ya see I am itching to get on with my personal project console and simply too impatient to wait for shipping of a cygnos (if I can find one) or even for the release of the DemoN and inevitable wait for suppliers to get orders out.... So I have decided to give it a go anyway!

I have been going by this image for the switch between onboard NAND and XD Card and it has given me some interesting results so far... Not too sure if its normal or not so thought I would ask the experts.



I dont have the switch or XD card in place, nor do i have the red wire cabled in. I am purely working with the mainboard, the resistors, the purple and orange wire, an for testings sake... a 3.3v LED

I have cut the trace and wired the orange and purple wires with 2 resistors as shown in the image and created the two following situations;

Switch Wires Joined - I get a 'Ding' But No Boot (assumed trying to find the non-existant XD Card)
Switch wires open - I get a Boot on OnBoard NAND

For experimental purposes I proceeded to solder a 3mm 3.3v LED in between the orange and purple wires. I now get a successful boot to the onBoard NAND and the LED will flash sort of like a read/write indicator to the TSOP when I interact with the dashboard.

Whats confusing me is the fact that before when i had the switch wires joined it didn't boot and I assumed it was looking for the XD card. but now joined with an LED in place which I assume creates the same kind of circuit It boots successfully every time....

Have I not cut the CE trace properly? could a cold solder joint have caused my initial failed boot? Does anybody know if the console should boot XD card NAND or onBoard NAND with the orange and purple wires joined?

Any advice would be appreciated


EDIT
Just to confirm, I have now removed the LED and we are back to the first situation (Wires Joined = No Boot / Wires Open = Perfect Boot)

[gy-repairs]

OK I have been doing some more reading, testing and metering....

From what I can gather having the wires joined *should* cause the console not to boot as it is pulling the CE pin of the onBoard NAND high to 3.3v (thus disabling it)

With the wires open the NAND is allowed to operate normally via the resistor. (and of course the reverse for the XD card NAND)

I am assuming that when I had the LED in line with the wires it was pulling the 3.3v which *should* have disabled the NAND thus allowing it to operate normally? I am not sure about the last part. Thats just speculation...

Can anybody please confirm this so that I can call it a success and secure the connections?

Thanks in advance

[gy-repairs]

OK so from my reading this is how I envisage the circuit.... Can somebody please confirm it for me?

[MagnusHydra]

shouldn't u cut the top smc line? From what iLLNESS says here.
http://www.xboxhacker.org/index.php?topic=16997.msg127795#msg127795

the CE line from the original nand does go both ways from the nand itself. i had the resistor on bottomside removed which wasnt sufficient as the bottom nand was still connected directly to sb ce.
so, now ive done the trace cut and all is well with both resistors
thanks

I am trying to figure out why u cut the trace when u could of removed the resister for what ur doing. Also by not cutting the top CE like to the SB ur original nand would always turn on right?

[gy-repairs]

Nope, if the wires were joined it would not boot at all. I did find that information from iLLNESS. Unfortunately the following events accounted for the demise of my 360 slim.

In retrospect, removing the resistor would have been the more intelligent approach. However, I will be attempting this again soon with the new information and past experience I will try going down a different route with it haha.

Thank you for the input

[iLLNESS]

shouldn't u cut the top smc line? From what iLLNESS says here.
http://www.xboxhacker.org/index.php?topic=16997.msg127795#msg127795

the CE line from the original nand does go both ways from the nand itself. i had the resistor on bottomside removed which wasnt sufficient as the bottom nand was still connected directly to sb ce.
so, now ive done the trace cut and all is well with both resistors
thanks

I am trying to figure out why u cut the trace when u could of removed the resister for what ur doing. Also by not cutting the top CE like to the SB ur original nand would always turn on right?

with the 360 slim, removing the resistor just disables it from being pulled up. the nand is still connected to the southbridge so there is no way to isolate it.

if you look at the nand CE pin it actually has two traces coming off of it. the nand ce pin connects to the southbridge on a trace that goes under the nand, then the trace that you can see coming off the pin is just the pullup. so, you can either lift the pin of the nand or cut the trace mentioned in the picture to isolate it from the southbridge. if you lift the pin though you will need to pull up the pin with the 10k ohm resistor or solder it to the trace again and cut the trace as well.

there is many ways to do it but quite simply the easiest way is what is shown in the picture if you have the skills to solder to the trace.

sorry and by picture i mean this one: