JTAG Martin C's 'Troubleshooting NAND-x Guide' results - Advice needed please.

[castingflame]

After getting the . . .

J-Runner v0.2 Beta (289) Started
Version: 10
Flash Config: 0x00000000
Can not Continue

. . . error all yesterday today I decided to fault find using the guide Martin C wrote. I removed the Nand X QSB and measured the results.

Point (on Martin Cs' guide) - Voltage, Resistance

1 - 1.56v 100k
2 - 2.99v 88k
3 - 0.067v 1.2k
4 - 0v 80k

5 - 3.22v 1.9k
6 - 0.88v 5.4k

R3B14 (equiv) 32 Ohms
R3B15 (equiv) 32 Ohms






Can you confirm that pins 6 and 7 (J2C1) are connected together? Can't seem to find a good enough photo Online to check.


J2C1.3 - is only 0.067v. Is that ok?



The process I followed is the following;

1. Connect JRP to PC (see the logo appear in J-Runner)
2. Connect the JRP to the wiring to QSB's and R-JTAG board plug
3. Plug the console in and leave in standby mode.
4. Try to read the Nand in J-Runner


At the risk of a stupid question . . . . . As a side, could I just plug the JRP into the QSB's with the R-JTAG completely disconnected?



The console powers up to the NXE ok. I believe it is stock not Xell as it does not boot into xell with eject. A very strange thing is that I can not sync my controller anymore. However I do see the opening/closing when I hit the eject button.

Have also tried writing the V2 firmware to the JRP. It does show the logo in J-Runner and reports Version 10.


I have gone round in circles so many times now. I have had the console R-JTAGed 2 twice sucessfully now but Ive not gotten to the point where it is all working 100% buttoned up in the case.


If the readings are within range would the Nand shorting trick be of any use?

Very confused and frustrated. Been at this for 2 weeks!

thank you.

P.S. Don't assume I know anything at all, just incase I have made a glaringly obvious mistake!

EDIT: Just to mention that when I soldered the QSB's (top side) on I could read and write the Nand fine initially.

 

[Martin C]

C1D7 is missing, which won't help you.

You'll need that replaced first and foremost.

 

[castingflame]

Thanks for your reply.

I notice on a previous thread that you said C1D7 that "is a filter cap for 5v standby". A few places online mention C1D7 as being 0.1uf, 6.3v, 10% in value. Not sure if that would be the same for my board though. Any reason why I couldn't use a small ceramic as I dont have any smd type or would it just be better to order some?

EDIT: It mentions in the post below that it is 4nf which is obviously 0.004uf. So these values are wildly different.

http://www.xboxscene.com/articles/fix-lpc-capacitor.php

I have also seen a few other values. I have a capacitor meter but unfortunately no capacitor to test!

 

[castingflame]

Just found a XENON schematic.



It also mentions that it is 0.1uf, 6.3v, 10% in value. Acording to the diagram it does look like a filter capacitor. While I understand that it needs replacing, I believe that I have already communicated with the nand previously without this and that others on the TX forum have also done so. I would be more worried if I were getting read / write errors but I am not getting that far.

But, this is just my thoughts nothing more.

 

[castingflame]

I have since installed my Sonus360 just so that I could test out my JRP. It programmed and verified the Sonus audio file sucessfully.

 

[Martin C]

J1D2.3 is too low and might indicate an issue with the SPI in the southbridge. Yes, it's possible to have a borked SPI section of the southbridge and the console to still work.

 

[castingflame]

Lol or I'll cry. Disconnected topside QSB's now the console won't power up! Checked everything before I went near the Power . . .

Guess I'll keep trawling the forum. Going to remove everything and try and breath some life into it again. If I can get it going I will try once more with my spare new QSBs to get some comms with the nand. If it is still the same I will cut my losses and leave the unit as stock.

Dissapointing after buying 2 x R-JTAG kits and spending 2 weeks of my life doing it. I have obviously made a pigs ear of all this. Twice was working running RATER . . . .

Worse thing is it should be well within my comfort zone to do this . . . . . . . obviously not at the moment

 

[castingflame]

Well it's back to life.

Also soldered a filter capacitor in place but still no comms. Tried reading the voltage on point 3 further down the track but it still has the same value.

I guess I will have to call it a day. Not sure if its worth spending anymore money on the board replacing the southbridge.

 

[Martin C]

You can bypass the SPI by wiring up a DemoN and using that for read/write.

 

[castingflame]

Sorry for the late reply. Got married and been on honeymood etc . . .

Thanks for the suggestion about the Demon.

Would I be correct thinking that I would have a single working nand (the demon) and it not be switchable? Would I use the standard Phat Demon install method?

Just wanted to check I understand this correctly before I order one.

 

[Martin C]

Congratulations!

If it's just the SPI which is the problem, you can use the DemoN to read/write the 360 NAND directly and once done, remove it.

 

[castingflame]

I'll give it a go and report back to the thread.

Thanks Martin.