Help with Jtag

wotzgoingon

Hey im getting error E79 after doing a Jtag. Its done with the Nand-x kit and is an Xenon. I tried Xellous first then Xellous with Xell then i read a guide which said he kept getting E79 then Flashed with XBReboot and it worked for him so i followed that guide and didnt work so i flashed back to orig.bin and got the same error so it must be a bad solder or something.

I flashed back orig.bin this way:
NandPro usb: -w16 orig.bin 0

is that the correct way to flash back to original. Any haelp would be great thanx!

Reamer Fanny

If you've flashed back the original you'll having to remove the jtag wiring in order for it to boot properly

wotzgoingon

justryan wrote: »

If you've flashed back the original you'll having to remove the jtag wiring in order for it to boot properly

Oh right thanx didnt know that. Damn it but its all soldered together dont want to take it apart. But i may have to just to c if that E79 goes away!

Reamer Fanny

Xenon wiring is pretty easy to do, you can keep the wiring just desolder it and put it to one side. Then power on and hope for the best

Wez

You don't need to remove Jtag wiring to run stock dashboard! Don't waste the time..

I reckon it's a bad write or maybe something shorting (I'll let ya know when the head clears and I can think straight).

Try write Xell, update to Xellous and insert USB key with freeboot image named as "updflash.bin", then power on with eject. That should rule out write errors, then start ruling out other possibilities.

Merry Chrimbo!

docentore

check soldering three times, check the diodes direction.

did you flashed your kv with xell/xellous? did you get any bad blocks during flashing.

Wez

Actually, diode direction could be what the problem is as Doc said, would explain why everything went fine, except it won't boot. That rules out LPT/USB wiring and I notice diodes are nearly always what causes me this issue (if a connection hasn't come loose on my Jtag wiring).

You could take a dump of the nand with Orig.bin (or any file) on it and compare to the original file to make sure it's reading/writing correctly. Then that means it's just the Jtag wiring.

wotzgoingon

No diode correction would be correct as im using the kit that came with Nand-x. As its not components that came but surface mount components on a pcb board. So hard to connect them the wrong way. So i took someones advice i forget who and checked for continunity and everything was grand going over to the two diodes. So i checked the guide at the top of modding section and noticed there should be a direct connection on the two other points and that connection is not there. The reason for this is probably that xecuter put a switch on pcb to turn jtag off and also change between two resistor values and 0 resistor value for this connection. But even with the 0 resistor value i cannot get continunity betwwen these two points. I tried all the points on switch to shorting the run its good on 1 side but the point labeled j2d2.7 on the guide at top is where there is no continunity. So wot should i do should i scrape the contol pcb and put a direct connection or are those resistor values needed??

wotzgoingon

I was just thinking there but even with that connection not there when i flashed back to original it shouldnt give E79. Maybe its giving that error as all the ground screws are not connected and ground is giving odd readings as i didnt bother putting the xbox back together every time i want to test it.

Wez

Ah, I didn't even register the Nand-X part!

Ground should be fine, it's sorted once it's got the power cable in, the metal case is just easier to clip / solder ground to (for me anyway). The metal around different sockets or the copper pads around screw holes are perfect for getting ground also.

If you've any doubts about the Nand-x and the connection between J2D2.4 and J2D2.7 just try solder a bit of cat-5 or such between the two and try boot up (you can leave the Nand-x kit in place, this will bypass the switch). I've never once needed a resistor between those points, on any board (might just be me though).

Also, for continuity, ya just wanna check between J2D2.4 and J2D2.7 they just need to be connected, not to ground or anything else.

wotzgoingon

Yea i suppose i will just connect a bit of wire straight to the connections j2d2.4 to j2d2.7. But when i was checking continunity at j2d2.7 i had 1 lead at that point and i just for tha crack connected the other to the heat sink near by and there was continunity so i tried all other earth connections and there was continunity. I said that cant be right as why would they say connect to the small connetion when there is loads of large earth connections to connect to. j2d2.6 also has a continunity connection to earth. I know its not used but are these connections to earth meant to be there?? If not something seriously went wrong. My solder is good and there are no shorts.

Jimbobjoeyman

Im just throwing this out there and it probably isn't the problem but if its not your wiring and you've already flashed back the stock nand its worth a try.
It may be your south bridge chip,put a bit of pressure on it and see if the 360 will boot.
Its probably not the problem since it worked before you attempted the jtag hack.
But its definatly worth a try if none of the other troubleshooting stops aren't working

Wez

Yeh, there are earth points all over the board, the ones mentioned are just easy examples to solder onto (they're all connected). J1D2.5 is my least favourite on the board, was the very first wire I tried to solder onto (when learning to Jtag) and it's a bitch. I just use my Jtag tool and clip onto the metal casing instead, but any earth is good.

I spent 5 weeks on my very first Jtag, eventually finding out everything was fine it just had a real RROD. Trying to verify if it's a hard or software issue I have is normally my priority, then find out what to fix.

E79 is so typical when doing a Jtag though, so really suggests it's your wiring or it can't load what's on the Nand (i.e. bad write). Try connecting those 2 points and see what happens when you boot, let us know how ya get on.

wotzgoingon

Okay i got into Xell was trying to take pics of my key.(ITs really hard to get a clear pic) and then after about a min scree goes blank 2 flashing red lights the same as when i got E79.

So it has to be a hardware fault as the Nand must be good if i got into Xell.

Oh yea this is a second hand xbox 360 with original x clamp gone and four screws holding in the heat sink. Maybe it suffered from this already and somebody fixed it and just decided to die when i went at this.

Jimbobjoeyman

that could have been mentioned sooner :P lol
If its an x clamp fix like this its doing much much more damage than good http://www.youtube.com/watch?v=fM4TEIZqOso
because it pulls the heatsink down further than its supposed to go and basically messes up the solder joints over a period of 2-3 months because it bows the board down.
quick fix without damaging the console would be this http://xbox-experts.com/tutorial/team-hybrids-ultimate-xclamp-fix-released/
the proper way about it would be to have it reflowed or reballed and either re-install the x clamps or do the hybrid x clamp replacement

Wez

Bingo, Xell doesn't have the P.O.S.T (power on self test) which results in a red ring. If you can boot Xell the Nand's fine but you've got to sort the damaged connection.

Basically, invest in the Hybrid Ultimate kit and patch your nand to run the fans at 100% (360 flash tool 0.95 etc does this, even on non-jtaggables FYI). You can also wire the fans upto 12v using many different points on the motherboard. You need to have them running full speed to keep your Jtag alive. It's worth investing in Arctic Silver 5 for bonding your heatsink to the GPU & CPU!

When you get it repaired, install XEXmenu or FreeStyle Dash and it'll show the temperature they're both running at.

wotzgoingon

Yea there is definetly a short between j2d2.7 and ground as ive another xbox non jtaggable and opened it up to c if that was meant to connect to ground and sure enough it was not. There is 3 capacitors 2 beside each other and the other the opposite side of that connection kind of under the heat sink but u can still kinda c them ive the heat sink off on both and on jtag xbox between j2d2.7 there is continunity on both sides of all 3 capacitors while on other xbox between j2d2.7 and the 3 capacitors only one side of the 3 capacitors have continunity as the other side is ground. At first i was thinking maybe the 3 capitors are gone but thats highly unlikely. I tried tracing the tracks but u would need a good magnifiying glass with lights(which i dont have) Unless there is a short under the GPU.

wotzgoingon

I resorted to getting the Xenon schematic and can follow it all around to chips and everything but i cant find V_MEM which is circled above. It comes up on alot of the pages so i assume its a + power supply like 5v or 3.3v but dont know for sure. I looked through all the pages and cant find where it goes unless there is a power supply page missing as there are no voltages giving on any page. If anybody knows wot it is would u let me know thanx!

wotzgoingon

Im pretty sure now that V_MEM stands for Voltage supply for memory as it is going to all memeory devices so id say it 5v. But i have a direct short between that and ground somewhere. I still cannot find it on the schematic to confirm that its 5v or where the 5v comes from.

wotzgoingon

Im still looking for where this short with ground is coming from there is no direct connection between pins with solder that is shown. If only the components werent surface mount and i could remove some to elliminate the path and find exact location of fault but they are so small. i soldered surface mount b4 but some of these are even smaller. Oh yea i found where the V_MEM power supply comes from it comes from a Dual Synchronous Buck Controller. I'd say there is a few pages missing from the schematic as there is no voltages giving or location of where they come from. V_MEM is not 5v its actually a 1.5v supply. Also when going through schematic i found out the xbox 360 has a tilt switch wotever thats for! I dont know does it turn off if u move it from vertical or horizontal. Never actually tried!

wotzgoingon

Does anybody know where i could get the xenon pcb schematic??

Its really annoying me where that short between V_MEM and ground is!
There is no short comming from all 8 ram chips and none from the buck controller. ITs all pointing to the GPU page 17 of the schematic document. All it shows is V_MEM no resitor limiting the current going in or anything if there was it would be perfect as i could find the resistor and know exactly which track is feeding that part of the chip and then check the side going into chip and if there is a short between ground on the side feeding the chip then thats the problem.

wotzgoingon

Wot ever clown came up with internal pcb tracks! Might be good for a design point of view but when ur trouble shooting without the pcb schematic ur fúcked unless u had x-ray eyes of something!:rolleyes:

wotzgoingon

Okay i got FreeBoot working!:D
But for how long.

As on my Jtag xbox with the continunity tester between J2D2.7 and ground it bleeps and shows 60ohms so it wasnt a direct connection as there is a bit of resistance between it and ground. While on my other non Jtag xbox it doesnt bleep and shows 95ohms. So i went with this http://www.xboxhacker.org/index.php?topic=13777.0 fellas advice as he had the same problem and just went ahead even though that near short is there and it worked. But it is still on my mind.