Posted 05 January 2007 - 07:33 PM
I have an xbox where the 1 farad Aerogel capacitor is leaking and the xbox is FRAGging. I removed the capacitor and I am now looking into making this xbox work without it.
I have read on forums that you could have the xbox working without that capacitor. Is that true ? In order to test it, I have modded the mobo with the most recent chip, but the xbox is still fragging.
So I am wondering, since those capacitors are fragile and rare, can I have the xbox working without it ? If so, do I need to bridge the two connectors where the capacitor was with a wire or a resistance ?
Thanks in advance for your reply,
Posted 06 January 2007 - 12:18 AM
If you've removed the capacitor and the X-Box is still fragging, then there's a high possibility that a trace or two has been eaten away by the contamination from the cap.
The substance used in electrolytic capacitors is very corrosive, as well as conductive, and if left long enough, will corrode track, traces, vias etc. or destroy numerous componets due to shorting.
You need to thoroughly clean the entire area where the cap was located, using methelated spirits or isopropyl alcohol. Then using a magnifying glass, you need to look for any corrosion on traces, tracks etc.
You can use a multimeter to check for track, trace etc. continuity, but be careful: what you may think may be continuity in a trace, its possible that the trace resistance has gone high due to the properties of the corrosion.
Hopefully you've caught it before its caused too much damage, but there is the slight chance that one or more semiconductor componets have been damaged.
Please let us know what you find.
Posted 06 January 2007 - 07:14 AM
Thanks for the quick reply. I have tried to clean the leak from the board and will try some more.
It is hard to tell if traces have been eaten directly under the capacitor. For instance, do you know if the solder points of C7G9 and C7G10 are respectively connected together ? Even though I don't think this have much importance since the circuit of the clock is broken anyways, thats the only place where I see obvious corroded traces. I'll try to get the capacitor and correct the clock traces, but I think I have small hope for this mobo to work in the end.
More news to come.
Posted 06 January 2007 - 10:47 PM
Yes, they are respectively connected. C7G9 and C7G10 are basically one and the same. The only difference is that perhaps Micro$oft needed secondary component holes for a different lead spaced aerogel capacitor. There's also the possibility that it was perhaps intended for a button type backup battery. I know for sure M$ were going to use one, but they found that it was going to cost one dollar more to do it, so the canned the idea. Normal pre-production cost savings I suppose.
If its just a matter of corroded traces, you might be lucky and it should be fixable.
Please let us know if you find anything.
Edited by DarkMatter, 06 January 2007 - 10:49 PM.
Posted 06 January 2007 - 11:10 PM
First pic is the top:
Here's a pic of the bottom:
Just shows what capacitor leakage can do.
Posted 07 January 2007 - 03:04 AM
I sure don't have anything like that on my board !
That sortof give me hope for my mobo
I heard there was some projects going around to replace that capacitor with a battery, did you hear of any that actually worked ?
Thanks and I'll post when I clean the traces and install the new capacitor.
Posted 09 January 2007 - 09:42 AM
Posted 15 January 2007 - 02:44 PM
The only option i still haven't tried is to flash the TSOP, which seems to be quite a job...
Any thoughts anyone ?
Posted 15 January 2007 - 11:24 PM
You've just introduced a short circuit. What ever you do, remove the wire, otherwise you risk damaging the PSU.
If you haven't found any damaged or broken traces, then the cause of the fragging my not be due to the aerogel caps leakage, its probably elsewhere or the leakage has already damaged a semiconductor component or two.
Give me a day or two to check what semi's may have been damaged and I'll get back to you on this.
Posted 16 January 2007 - 03:07 AM
I took a hires closeup of the capacitor's location... Geez, when things are close up its quite ugly...
I guess you can clearly see where the capacitor leaked (toward the upper-right up to the other locator c6g1). The region directly above c7g10 is ugly, but the connections seems ok...
Thanks a million for the time and care you are taking into this forum. Your are a great community person!
Edited by Chancer, 16 January 2007 - 09:53 PM.
Posted 16 January 2007 - 04:16 AM
Ok. check the revamped picture below.
These two transistors look suspect. From what I can see they look as if they have a small split in them. Or is that just aerogel remnants??? Try cleaning the black surfaces of those two indicated transistors. Check with a magnifying glass to see if there are any cracks.
Please let me know what you find, then we can go from there.
Posted 16 January 2007 - 09:28 PM
So here you can see the transistor a bit better... I checked and I cannot find any cracks or something similar on most on the board.. I guess we will have to look into something else...
Posted 19 January 2007 - 03:47 PM
I've also tried to resolder the modchip, just in case, but that didn't fix it either.
The xbox is still booting once (the modchip's led lights up twice) and then boot again (the mod chip lights up once) and then reboot a third time and the flashing red and green with the modchip's led turned on.
(even though I've mentioned the modchip, the problem was the same thing without the modchip... its just for indication)
Please, if you still have time for this or if you still have ideas that I could try, thats pretty much all I still have to do before giving up :-)
Thanks a million!
Posted 20 January 2007 - 12:05 AM
Here's what you do:
Set your multimeter to diode test and short the probes together. Note the reading, as this will indicate a short circuit.
Now place a probe on one leg of a transistor, and the other probe on another leg of the same transistor. Note the reading on your meter.
Now, leave the first probe where it is, then with the other probe, place it on the remaining leg of the same transistor, note the reading.
Do this with the rest of the transistors, making sure you don't get a short circuit reading on any of them.
Don't worry about which probe goes on where, as we are not doing a bias or punchthrough test on them, so polarity isn't an issue here. We only want to make sure none have shorted.
Please let us know how you get on.
Edited by DarkMatter, 20 January 2007 - 12:06 AM.
Posted 23 January 2007 - 02:15 AM
Thanks for the input. I tried to do what you posted and none of the transitors show a short circuit. Some have readings that show some connectivity, but none have a reading similar to a short circuit.
So I'm guessing that is not it. Is that right ?
Are there any ways to see if the PSU or another main component works or not ?
I looked for cracks, but there are none.
Thanks again !
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