ANSWERED BB Jasper working For a month then dead

[N.E.Modz]

hi,

as the title says, I rgh'd a BB jasper a month ago, been working fine until yesterday. Its has power to the coolrunner but will not boot (totally dead)

I have double checked the connections/points with USB Microscope, especially STD_CLK (B connection) and I have continuity all the way thru.

Ive tried a new power brick & a different RF board but still nothing.

I was gonna try a few things to try & sort it.

use alternate point for "B" connection point &/or flash back original nand to see if it will boot
Which one should i try first ? or is there something else I can try before doing these ?

Any suggestions would be helpful

tah

dale:wink:

 

[TilVl]

Check the mosfets.

 

[N.E.Modz]

Check the mosfets.

which ones would they be ?

dale:wink:

 

[TilVl]

Check the ones in front of the CPU. There are 2. Had this once before on a friend xbox. Was the one closer to the ROL board. Here's a check list google provided when I had the problem. Sorry don't remember the site. saved it to notepad.

1. Check all exterior ports for any obvious signs of bridged / bent pins or missing / damaged components from cables being 'jammed' into the ports.

2. Try multiple power supplies

3. Try turning the console on with the 'eject' button. If that works, then replace the RF board.

4. Leave the console turned on for 15-20 minutes and feel the various components on the motherboard to try and find a 'hot spot' where a potential short could be occuring.

5. If the power brick turns Red, then it's potentially a short on a 12 volt line. If the power brick stays yellow or green, then it's potentially a problem with a 5V line.

6. The short may be occuring on the voltage regulators / mosfets near the Southbridge area..specifically U5B1 and U5B2. They are located by the fans near the middle of the motherboard. They should measure 3.3V and 1.8V at the larger tabs (opposite the 3 legs at the back of the MOSFET).

7. If the above Mosfets measure o.k, then Reflow the Southbridge.

8. In one rare instance, another poster noted that it was a bad DVD 12 volt power adapter cable....try swapping it out.

9. Look for cut or scratched traces on the mobo near where the xclamps are located as someone may have damaged the board trying to remove the clamps.

10. If 360 turns on, and flashes 3 red lights 'Immediately' (fans do not spin, and Psu shows red light)...it could be the Q3F1 mosfet NTD4813NHT4G. Secondary for this situation is usually 0001 or 0002.

here's some info about mostfets
http://forums.xbox-experts.com/viewtopic.php?f=6&t=538

Good luck.

 

[N.E.Modz]

there is definately no shorts (powerbrick does not turn red). I have checked then under microscope and there doesnt seem to be any physical damage and there is no burnouts on resistors surrounding them.

this has got me baffled

dale

 

[TilVl]

As said. Check the mostfets. Or remove coolrunner turn back to stock to see if it works.

I think its a mosfet problem.

Sent from my SGH-T839 using Tapatalk

 

[N.E.Modz]

As said. Check the mostfets. Or remove coolrunner turn back to stock to see if it works.

I think its a mosfet problem.

Sent from my SGH-T839 using Tapatalk

Im gonna flash back original nand first before i start to feck about with the mosfets.
the only problem now is that I get "cant find usb device" with the qsb's, so Im gonna have to remove qsb's and do direct wire nand flash

thanks anyway

dale:wink:

 

[litnin]

Try resoldering the STD_CLK. I had same problem with a couple of consoles and this was the problem. Dry solder joint i recon. I've since changed my flux and have no problems.

 

[Martin C]

Im gonna flash back original nand first before i start to feck about with the mosfets.
the only problem now is that I get "cant find usb device" with the qsb's, so Im gonna have to remove qsb's and do direct wire nand flash

thanks anyway

dale:wink:

MOSFETs wouldn't stop you reading/writing to the NAND.

Moving from QSB to wires won't make any difference either.

as aleady mentioned, check STBY_CLK. Desolder if needbe.

 

[N.E.Modz]

MOSFETs wouldn't stop you reading/writing to the NAND.

Moving from QSB to wires won't make any difference either.

as aleady mentioned, check STBY_CLK. Desolder if needbe.

checked STBY_CLK, had continuity, removed qsbs & tried alternate point on underside of mobo but still dead

dale:wink:

 

[Martin C]

Check my sticky on troubleshooting NAND-x errors.

If these all work out, it's possible you've corrupted the SMC and you need to do a bad flash recovery.

 

[mafia 5k]

i had same problem fixed by using a airosal can (compressed air duster) and alchohal not saying this is a fix in your case ... but it worked for me

just glazed the hana area sprayed it out with the compressed air it booted right up must have been a microscpic solder ball bridging it :wink:

 

[cicero44bc]

TilVi and Mafia5k, do you mind if I add your tips to a troubleshooting post I've put together http://www.team-xecuter.com/forums/showthread.php?t=78951 with all due credit to yourselves and mentioned sources?