Fake Caps in Xbox 360

[Galraedia]

I decided to take one of the Rubycon capacitors out of a phat Xbox 360 with a Zephyr motherboard and noticed that all the Rubycon capacitors near the CPU were fake. The capacitors in question are Rubycon MFZ 680uf 6.3V and they all have a bullseye bottom, something not found in genuine Rubycon capacitors. None of them were leaking, they all have the K top, and the system has never been opened before. It appears Microsoft was using fake capacitors in the Xbox 360, or the Chinese facility where the console was manufactured in was using them and passing them off a genuine. Just thought I'd share this as I was surprised to find out they were fake and started taking all of them out to see if any of them were real. Every other capacitor on the board appears genuine except for these.

[stj]

Re: Fake Caps in Xbox 360

or maybe they are real,
MFZ are "special" crap made for bulk manufactured devices - so who knows what the details are.
other than they dont last.

[momaka]

Re: Fake Caps in Xbox 360

Hi Galraedia and welcome to BCN!

No, Rubycon MFZ series are *not* fake. They are just a custom order only made for the Xbox 360's. From what I've gathered about these from posts over here over the years, they are essentially almost the same thing as the MCZ series from Rubycon, which are their lowest-ESR electrolytics they ever made, as far as I know. The supporting evidence is that MFZ is often interchangeably used with Nichicon NZ, another ultra-low ESR series (actually, the lowest ESR series that Nichicon ever offered.)

Yes, they look a little dodgy with their "bullseye" bungs, but they are 100% real. And in particular, these 6.3V, 820 uF sizes are actually quite resilient / reliable - at least I haven't had one fail in operation yet. Now, the slightly older Xbox 360's that used the Rubycon MFZ 6.3V 2700uF caps - those are very failure prone. I used to re-use these 6.3V 2700 uF caps from scrap Xbox 360 motherboards in all kinds of recapping projects. Many of them have failed or are just starting to fail now. Interestingly enough, the ones that always seem to fail quicker are the ones that didn't see much use. The ones that I used most often didn't fail or only started failing recently. So in a sense, they seem to not like sitting on a shelf without use, kind of like United Chemicon KZG series.

Anyways, I did a write-up about the failure of 6.3V 2700 uF MFZ caps not too long ago. It can be found here:
https://www.badcaps.net/forum/showpo...&postcount=991

Beware that these are not the only caps that fail on the Xbox 360 motherboards. The other ones that fail very often are 6.3V 2200 uF Nichicon HZ with date codes starting with H05xx. As of today, all of the H05 6.3V 2200 uF HZ I've pulled for re-use have failed. Not a single one standing. Interestingly enough, anything H06 and newer I have not had a single failure. So with Nichicon HZ and that specific capacity, the issue is isolated only to H05 and older date codes (known problem with Dell motherboards too back in the day.) I noted the issue here:
https://www.badcaps.net/forum/showpo...&postcount=993

And lastly: Sanyo WF series. With these, the size / voltage / capacity does not matter. They ALL seem to fail just the same. Some of the really early non-HDMI Xbox 360 motherboards used to use these in 16V 1500 uF size. They are not found very often, but they do exist out there. I ran into a few of those too during my years of scraping dead Xbox 360 mobos. All of the 16V 1500 uF Sanyo WF I've pulled for reuse have gone bad, just like the H05 Nichicon HZ series in 6.3V 2200 uF size. Details here:
https://www.badcaps.net/forum/showpo...&postcount=970

Hope this helps in some way.

In any case, the Ruby MFZ you show above (6.3V 820 uF) are extremely unlike to be the issue if your Xbox 360 motherboard is not working. Chances are, it's a GPU issue / failure... or RAM a little less often. The stupid small heatsink that MS used on the GPU is the #1 reason these 360 motherboards fail so much. Nothing you can do about that, other than removing the optical drive and re-attaching it externally (or removing it altogether) and changing the GPU heatsink to a proper full-height one... oh, and speeding up the fan too. The whole cooling design of the 360 is absolutely piss-poor. As nice as they looked, I never shed a tear for scrapping so many.

[Galraedia]

Re: Fake Caps in Xbox 360

Weird. Kind of makes me wonder if these capacitors are rebranded and licensed by Rubycon to use their name. I've never seen Rubycons use these bottom bungs before as they are notoriously used in low quality capacitors and fakes.

There was nothing wrong with the motherboard. I wanted to gift the Xbox to a friend and opened it up to clear out any dust and replace the thermal paste when I noticed that I must have accidentally gotten Arctic Silver thermal adhesive on one of the capacitors years ago when I put a heat sink on the Hana chip, which had a problem that require me to reball it. The adhesive on the capacitor was bugging me so I took it out to replace it and noticed the bottom bung. You're right about the phat Xbox 360 having a poorly designed cooling system that places the GPU directly below the dvd drive. However, it's the combination of that and a defect with the metal enclosure which has 2 of the bottom stands higher than the outer edge where the motherboard sits along with the x-clamps that causes the motherboard to flex and the chips to lose their connection. I've sanded down the two stands and used the Hybrid eXtreme Uniclamp to prevent the red ring of death on all the phat versions of the Xbox 360 I've worked on and I've never had an issue. That along with downloading games you want to play from the disc to the hard drive not only makes games run faster, it also lowers the amount of heat produced by the dvd drive.

[momaka]

Re: Fake Caps in Xbox 360

Weird. Kind of makes me wonder if these capacitors are rebranded and licensed by Rubycon to use their name. I've never seen Rubycons use these bottom bungs before as they are notoriously used in low quality capacitors and fakes.

They can't be, because the only other manufacturer that ever made such ultra-low ESR/impedance capacitors are Nichicon with their HN and HZ series. Panasonic has FL series and United Chemicon has the KZG/KZJ series... but from what I remember from datasheets, neither of these are quite on par with Nichi HN/HZ or Ruby MCZ and MFZ. And any Chinese/Taiwanese brands with "ultra-low ESR" series went only about as good Rubycon MBZ / Nichicon HM / UCC KZG if even that much. I think OST RLA is the only one that has anything close to the HZ and MCZ series. RLA are notoriously unreliable, though. So if that was the case, all MFZ should have failed a lot quicker.
And again, at least in my experience, the 6.3V, 820 uF Rubycon MFZ caps have been 100% reliable so far. The 6.3V 2700 uF - not so much... yet these do have the proper Rubycon rubber bungs.
So the bungs may be weird on those "skinny" MFZs... but probably Rubycon saving on some costs there without impacting the quality of the product.

That along with downloading games you want to play from the disc to the hard drive not only makes games run faster, it also lowers the amount of heat produced by the dvd drive.

It also doesn't add wear and tear on the DVD drive anymore, so this is definitely a must-have mod.

[nick122]

Re: Fake Caps in Xbox 360

Okay, I just wanted to clear a few misconceptions regarding the 360, since there's a lot of misinformation. My friend and I have been investigating why the 360s failed so often and we've come to a conclusion that the GPUs are defective by design. It's very rarely the BGA that's the issue, but the tiny bumps that connect the die with the interposer.
Our theory is that Ati used a very low Tg underfill (70c as far as we can tell)
Underfill is the hard substance which is used to support the bumps due to differences in CTE (coefficient of thermal expansion) of the silicon die and the organic interposer. The underfill fills in the gaps between the bumps and provides structural support during expansion and contraction as the chip heats up and cools down.
Every underfill has its Tg, which is the temperature at which it stops being effective and becomes soft. The one used in early 360 GPUs seems to have a Tg of 70c, which means that the bumps lose most structural support above that temperature. The regular operating temperature of the GPU is around 80c, and that's where the issue arises. After a few dozen thermal cycles the bumps begin to fail, and you get the red ring.
The revised GPUs started coming out around April 2008 (date code 0818 and up) and those are pretty much bulletproof, haven't seen a single failure out of hundreds of consoles. They use a High Tg underfill (130c). You can check yours with a blacklight, if the underfill appears dark, it's the revised chip.
You can have a look at xenonlibrary.com for more info if you're interested

[momaka]

Re: Fake Caps in Xbox 360

Okay, I just wanted to clear a few misconceptions regarding the 360, since there's a lot of misinformation.

Thank you for the info, nick!

I think you're correct in finding that most Xbox 360 failures are from the GPU chip failing, and particularly the underfill. I myself have suspected the same for quite a while now... and not only for the Xbox 360, but for many of the older era GPUs. RoHS BGA, while weaker than the older lead-based stuff, is still quite strong. If it wasn't, I think we would have seen a lot more motherboard failures in desktop PCs. Starting with AMD socket 754/939 and Intel socket 478, the design of the mounting mechanism for the heatsink on these regularly warped motherboards to hell. Yet failures were rare. If the RoHS BGA was as weak as people touted it to like with the Xbox 360, then those motherboards would probably not stand a chance of even getting their cooler mounted once before a failure. So I think the issue is indeed not with the BGA from the substrate to the board, but rather the substrate to the chip itself (which was only supported by the underfill.)

That being said, my suggestion for anyone still owning an older (and still working?) Xbox 360 is to improve the cooling as much as possible to prolong its working life. Best way IMO is to turn up the fan speed (hot-wire the fan to 9-10V) and/or also remove the DVD drive and install a 2nd CPU-sized aluminum heatsink on the GPU (don't use the Copper heatpipe one on the GPU, as I don't think the base is wide enough to cover both chips on the GPU.)