Broken 360, 12v Short, Mosfet Blown ? Options

[FragZero]

Yesterday i was working on my xbox 360-> atx case conversion when my xbox decided to rrod

3 rrod => Error Code 0001

Measured the psu when xbox on ,

5V OK

12 V -> 0V

Measured the resistance between

5V and ground -> Ok (several Kohm)
12V and ground -> several ohm, aka a short somewhere
5V and 12 V -> Ok(several Kohm)

After some searching i found that grounding 5V could destroy a mosfet. But this isn't my problem, i have enough resistance between 5 and 12 v, if those mosfets where blown it would be alot lower

So if Found this topic

http://forums.xbox-scene.com/lofiversion/i...hp/t634608.html

I tried desoldering Component Q6B1 ( i can get spares in a shop nearby) but still a short between 12V and 0

Any idea what i can do to fix this problem ? i'm not going to desolder all the mosfets to find the defect one . although i am using a atx psu so i have 3.3V 5V 12V. If you think that you know what mosfet might cause this, and it's used to converted power to 3.3 or 5V i can desolderd the mosfet and connect a wire from my psu.

[FragZero]

Need help

[Mholt215]

Sorry for the huge bump, but I have the same issue now. We really need to find out whats causing this, but what sucks is that theres so many components that could be the issue.

[adrenaline_X]

Sorry for the huge bump, but I have the same issue now. We really need to find out whats causing this, but what sucks is that theres so many components that could be the issue.

Little late, but i jsut had a similar issue.. I'm waiting for my parts to arrive.

With the xbox off, check the resistance between each leg on the mosfets going down the right side and along the back by fans.. if their is no resistance from both front legs and to the back, you found the mosfet that is dead.. I set my multimeter to "continuity check" so it would beep at me and found q6b1 to be shorted.. waing for parts to arrive to replace and test.

If this shorted out after a x-clamp mod, you may have the clamps too tight.

[xbmediaby]

hate to bug a person but my searches in the forum led to you... I was testing my 360 dvd leads and shot 12v to either ground or 3.3-5v now no power plug the supply up (amber) press power fans spin for a second then nothing pwr supply goes red. do you think this is a mosfet and would you off the top of your head know which one to search for. thanks for your time

[ruddlescounty]

hehe - sounds like you did the same as me!
i was trying to suss out a dvd drive not opening by shorting pin 3 to 5, i slipped and saw a flash - now my box wont boot! i'm guessing i took the pin 6 to gnd (3.3v).
does anyone know if this is likely to be a mosfet problem - & if so any help on which one?
so annoyed as it was jtagged too

[drewis]

ouch ruddles.. that blows man. hope u get her to work... guess youre gonna have to find out which mosfets/caps are on the 3.3 rail..

[prime2010]

I have a 0001 board atm with everything 12v shorted. Total bugger. Its a new Reball and the reball job is pretty darn good and I don't think GPU can short ground out like this. What occurs was once the board bowed badly but from what I can see no major damage occur. The system use to be error 0021, then after the incident it was 0001.

I don't believe its the MoFETS, I just can't put my finger on what could be shorting it so much, nothing visual. Wondering if anyone has some key places to check?

I already checked the 5v and 3.3 and 1.8v lines, they all seem ok, just everything 12v is broken, I have tested with another PSU as well so thats no the issue.

[MadMaxGR]

Well you make me wonder... you say you don't think its the MOSFETs but you didn't really check them.. did you? If you know more than anyone here, then why did you post in first place? CHECK before you assume ANYTHING!

[prime2010]

I resolved this problem by reballing the Southbridge, all good now. well except the 0021 error LOL

[mgeno216]

Well I have never dealt with that problem, but you could try that freeze spray aerosal can. It put like a cold frost on your moboard and where ever the spray isn't melted of by the hot componets (the resistance), means look there for a short. I am not sure if that would work, but it is an idea.

Mike

[LordX]

Well I have never dealt with that problem, but you could try that freeze spray aerosal can. It put like a cold frost on your moboard and where ever the spray isn't melted of by the hot componets (the resistance), means look there for a short. I am not sure if that would work, but it is an idea.

Mike

freeze it , too much freezing then hot means will be watter , sounds not so safe.

[chrjd12]

I have ran into this problem a couple of times. It usually is a mosfit. Problem is tracing it out does take sometime unless you have great equipment. Wish I could tell you eactly which one but honestly it could be any of them.

Also I assume you checked these as well:

Check the caps make sure none are blown (see if there is a bulge)
Check the traces (visual) make sure you didn;t scratch a trace accidently
Check the PSU units (exchange for a different one)
Check where the psu connects to the 360 - (I had an xbox that had a broken plastic piece and the metal was touching ground when you pushed the plug into the xbox.

Hopefully this helps

[LordX]

yes true in most cases this a mosfit, but how to tell without any equipment...

[mgeno216]

freeze it , too much freezing then hot means will be watter , sounds not so safe.

No it is not water, it is CO2. It doesn't stay in a liquid phase is just sort of frosts the moboard then turns straight into a gas. I forget the chemistry behind it, but it is similar to dry ice. I know I have seen it at radioshack.

Mike