ANSWERED Troubleshooting Guide - No power / Completely Dead / Power and STBY_CLK Issues FIXED.

cicero44bc

Full Member
Dec 1, 2011
67
0
Stratford Upon Avon
Firstly thanks to all those who have posted very useful info on these forums, you've created a pool of knowledge and amazing support - because of which I have never had to ask a question, thank you!

Secondly apologies this is in this section. As I am technically ranked as a noob I can't help it.

For me to begin giving a little bit back; This guide is designed to be a catch all in terms of possible causes of the described fault -

The issue/fault being addressed here::

Your xbox may run for a period of time then cut out like the power was pulled. Then run for a shorter period and cut out again. Then after that, not power on unless you remove the PSU from the xbox and leave to stand for 30mins OR it just wont turn on at all. This may be after days of working perfectly (as in my case). What you most likely have is a STBY_CLK issue - this is the part that point B on the coolrunner runs to on the HANA. I've checked a number of possible causes and saw a number of useful points in various posts and I thought I'd compile all I came across into one place to help those nice people that also use the search function before asking :)

So, if you are experiencing as above or it simply will not turn on at all;

Your points to check are -

* Dry solder joints - Your biggest saver here is to USE FLUX.
* Poor solder joints - See Image
* Bridges - Solder joints that span to points they shouldn't, OR joints in which the solder is left in a point and then touches the case when the xbox is put back together and gets warm.
* Lifted Pad and track caused by extreme over heating of a joint
* Broken STBY_CLK Track on motherboard - Can be caused by lifting the pad and/or slipping when applying the QSB.
* Blown/Dislodged R4B24 Resistor (at point B in install diagrams), caused by excessive heating and/or careless soldering.
*Cables running through coils - Thanks go to Uber
* Your RF Board
* Your PSU
* Southbridge

Troubleshooting Steps -

Grab your multimeter and test for continuity between point B on the coolrunner and the contact on the R4B24 resistor nearest the QSB.

Thanks again go to Uber for the original image.

This basically tests the whole line of point B. If there is no continuity then the fault lies on this line and your next port of call is to check small lengths within it; so B on the coolrunner to the highlighted point on the QSB. Then from that point of the QSB to the point on the R4B24 Resistor. After APPLYING FLUX reheat the solder until it reflows and test for continuity again and you should now be good.

A point well worth bearing in mind is your continuity could be good and it is still worth adding flux and reheating again anyway. Why? Because you could still have a dry/poor solder joint that is in contact when cool but is not when warm and therefor causes your xbox to cut out (as in my case!).

Compare your image to the below



Which is not my own image but is useful for helping to identify bad soldering and describes the causes.

Top Tip -

Let your soldering Iron warm up so it is very hot first - 5 maybe even 10 minutes. This allows the solder to reflow very quickly so you can avoid spending a long time holding your iron on your board and damaging your tracks, pads and surrounding compontents due to the heat having time to dissipate through them.

If you have one, use can use a soldering gun (carefully!) for the same reasons.

Lifted pad/track

If you did the above with the multimeter and still have a continuity error, chances are you have lifted and pad and or track next to the R4B24 Resistor. Refer to this very useful post on how to fix. Thanks again Uber!

Broken STBY_CLK Track on motherboard

Refering to the below image - The track that the pad that point B on the QSB is soldered to can be broken when excessive heat it applied during the soldering of point B causing a lifted pad as per above which can disconnect the pad from the track in some cases. It can also occur when one slips when soldering the rest of the points on the same QSB after soldering point B causing the pad to lift and the track to break. However it may not be obvious when troubleshooting as one would naturally check continuity as per above and all points can return good - even though the original track is broken. So test between the point highlighted below and the point to the left of the R4B24 resistor in the image above. You may need to (very carefully!) scrape of the lacquer of the track on the bottom left of the circle (as opposed to the top right which risks breaking the track) to get contact with the track. Again please do this carefully and lightly, just to expose the copper track. I soldered pins to my multimeter probes to make testing round my boxes easier, a bodge I am particularly fond of!



Blown/Dislodged R4B24 Resistor

Using your multimeter test your R4B24 value, it should be the same as the others in that strip at ~34ohms. I've seen a number of these issues being due to the resistor in question being fried or been dislodged. Luckily a 24p trip to Maplin can get you all fixed. Quick find M33R. Dont worry about it not being surface mount, it'll work exactly the same.

Cables running through coils

Refer to this post for fix. Thanks Uber.

Your RF board

If you have tried all above and still no joy try a different RF board. Although you can try powering on with your eject button I have read that your RF board if faulty can cause it not to turn on. This may be very coincidental that it should go at the same time as fitting/using your coolrunner, it has just been included here for completeness and as they have been known to cause the same symptoms.

Your PSU

If you have tried all above (not necessarilly the RF board part) and still no joy try a different PSU if you have another you have access to. PSUs are known to fail; still providing the standby voltage but not stitching when then xbox it turned on. Again this may be very coincidental that it should go at the same time as fitting/using your coolrunner, and again it has just been included here for completeness and as they have been known to cause the same symptoms.

Your Southbridge

The same way you can experience the RROD due to the state of the BGA on the GPU and CPU connecting to the motherboard, the Southbridge can suffer from the same problem. There have been people reporting 'x-clamp' fixes for the southbridge (which I not in a position to back) or having issues solved by adding a heat sink. I've just this moment fixed my falcon using a heat sink I salvaged from the southbridge of an old motherboard. It's been fine for 2 hours where it was turning off after 15mins previously and was dead for a period after that. A proper fix here would be a reflow, I am likely to persue that if this does not last, this in the mean time has got me working for nothing :)

I hope this helps some people, if so please use the thanks button it would be greatly appreciated!

Please feel free to correct me and add to this and I shall edit the post with due credit :)
 
Last edited:

KhaineGB

VIP Member
Jun 19, 2011
731
0
Liverpool, UK
Very good post. :)

The only comment I have is regarding heating the iron. Yes it's good to leave it for a few minutes, but make sure you tin it! I killed my first iron by letting it heat up for 10 mins without tinning it... a n00b mistake, but I now know better. With my solder station, I find that I can melt solder onto it within 2-3 mins... usually closer to 2. Get it tinned, then feel free to leave it a little longer, especially since tinning helps with heat transfer.
 

moshbear

Noob Account
Mar 11, 2012
3
0
Is use of a griddle recommended for SB reflow too? The closest I have to BGA rework is a $300 hot-air system at the nearest hackerspace, and there's no griddle.

Granted, the surface area of the SB is considerably smaller than the GPU, but is it still pretty important to have a warm underside there?