JTAG Falcon being strange

[wobblenuts]

I have a falcon that is giving me a hell of a time jtagging it. I bought it for $10 off a guy who said he previously had it jtagged, it died (didn't ask further unfortunately) and he was unable to get it working again. Now I don't know exactly what he has done to it but the board looks to be in surprisingly good condition and the solder points aren't annihilated.

Here is everything I know and everything it's doing:

- re-soldered on the underside, FT2U1, AUD_CLAMP and 3x1000 Ohm in parallel for 330 Ohm (measured with dmm).
- r6t3 alt point was soldered.
- 1ROL E79 on boot within a few seconds, every single time, no exceptions.
- DB1F1 is pulled off.
- have original pre-jtag nand. 360FlashTool says CB 5766, Patch 0 7371, Falcon v3.0
- put orig nand back on, boots right up with no problems, jtag wires left in place.
- no bad blocks found reading or writing.
- put dmm on J2D2.1 and .2, 1560 Ohm each.
- have tried straight wire, 100/200/330 Ohm on J2D2.3+7
- made my own xell with smc, tried some found on here ("AUD_CLAMP.rar" - aud_clamp only etc), same results.
- do not have the dvdrom, only have the board + heatsinks.
- do not have the cpu key unfortunately... he was unable to find it.
- in my completely-un-professional opinion the points are soldered on good, tested with dmm.
- to cover all bases I reflowed the gpu only, no change.

Now for $10 I'll get pretty invasive to find out what the problem is but I would prefer not to destroy the board.

Any ideas? I'm quickly running out of them...

 

[xColorado880]

Use a diode from pin 7 to 3 . Cathode facing pin 3.

I had a similar problem a few months back and this post on XBH helped me.

Good luck

 

[wobblenuts]

Oops left that part out, I did try that as well. I agree that if I do crack this nut it will more then likely be what works in pin 7->3.

 

[Martin C]

How are you running out of time? Surely you've not bought a faulty board to give to someone?

Flash the stock NAND and boot it up. Reset the settings (initial setup) and reboot. Re-dump the NAND and re open in 360 flash dump tool. Has your CB value changed ?

 

[wobblenuts]

How are you running out of time? Surely you've not bought a faulty board to give to someone?

Flash the stock NAND and boot it up. Reset the settings (initial setup) and reboot. Re-dump the NAND and re open in 360 flash dump tool. Has your CB value changed ?

I think you misread my last line, you should reread stuff before accusing people of being scammers lol

Anyway nope, nothing changed.

 

[Martin C]

I think you misread my last line, you should reread stuff before accusing people of being scammers lol

Maybe you should take your own advice. I was asking whether you had bought a faulty board to repair and JTAG for someone else, as I couldn't see any other reason why you'd be running out of time to get it fixed.

Back on topic, unless the person who had it before you changed the wiring after it stopped working, the only factor I can think of here is the GPU. TMS and TDI connect to the GPU itself via J2D2.1 and J2D2.2. I know you say you've probed these points but it could still be bad. You wouldn't see it in normal use as they're debug points.

Does the wiring look messed up at all? Can you take pics of the points which have been soldered to?

 

[wobblenuts]

Maybe you should take your own advice. I was asking whether you had bought a faulty board to repair and JTAG for someone else, as I couldn't see any other reason why you'd be running out of time to get it fixed.

Where are you getting the impression I'm running out of time?

Does the wiring look messed up at all? Can you take pics of the points which have been soldered to?

It was all removed when I got it. Everything was pretty clean, I cleaned it up further and redid everything. It is starting to look more and more like it is the gpu unfortunately...

 

[Martin C]

umm, because I misread the last line of your OP

:facepalm:

Hence the confusion!

If a JTAG console suddenly gets stuck at E79 and you can't see a physical reason for it, then the GPU is more than likely the fault.

The good news is that it's a falcon and you should be able to RGH it instead

 

[wobblenuts]

Yeah this has put me in a weird spot. I don't have the dvdrom, don't have the cpu key so I cannot make a new dvdrom and so I cannot upgrade to the latest dashboard to use it as a regular xbox. It's RGH or nothing...

Besides the 1.5k resistance is there any way to tell for SURE if it's the gpu? I don't plan on switching it as it's not "broken".

 

[Martin C]

Well if you have the original NAND, once you fit a coolrunner and boot to xell with it you'll get the CPU key. From there you can either RGH it permanently or use the CPU key to get the DVD key details and keep it as a retail box. Simples!

 

[wobblenuts]

Looks like I'm doing that. Thanks for your help.

 

[wobblenuts]

Picked up a coolrunner and to my surprise the bastard is fighting that too! The green light blinks away never booting into xell. I'm pretty sure my soldering is all good...

 

[Martin C]

how sure? pics please!

 

[wobblenuts]

Heres some shots of everything. I have redone it three times now shortening the wires, moving them around etc so its not pretty anymore Still green light blinky blink.

top board - http://img684.imageshack.us/img684/9792/toppu.jpg
bottom board - http://img62.imageshack.us/img62/6066/bottomnc.jpg
coolrunner - http://img12.imageshack.us/img12/328/coolrunner.jpg
blue wire - http://img210.imageshack.us/img210/1741/bluelc.jpg
green wire - http://img268.imageshack.us/img268/3693/green1in.jpg
green wire - http://img341.imageshack.us/img341/731/green2x.jpg
green wire - http://img843.imageshack.us/img843/1641/green3o.jpg
orange wire - http://img685.imageshack.us/img685/1916/orangejo.jpg
red wire - http://img836.imageshack.us/img836/3373/redmx.jpg
yellow wire - http://img862.imageshack.us/img862/2769/yellowh.jpg

 

[wobblenuts]

Managed to get it going. The solder points were all good, didn't have to touch them. The guy i got it from found the cpu key so I rolled off a dump with 360 multi builder 0.7 and it fired right up in 5 seconds. It also boots into xell reloaded now which is kinda wtf.

On a side note I got a nand-x off the guy and used that to program the nand. Holy f**k does it ever make the whole process of dumping/rewriting the nand less annoying. I just wish there was a linux version :wink: