Xbox One dead LAN IC

[Dannyx]

Good day folks. A friend of mine asked me to take a look at an Xbox One console with him. He's pretty good with electronics too and we worked together for several years in fact, so we went on this journey together to see if we can resurrect this junk box for Christmas (spoiler: we couldn't)

Initially we thought the power brick is bad, because of the way it behaves: LED on the brick turns white, then orange after a few seconds and it keeps doing this. The touch-key on the front of the box works: it makes the "ding" sound and the white logo comes on, but that's it: no picture on screen. The logo then turns off and the LED on the brick goes back to orange. It can even eject the disc when you press the eject button, so there is power getting through.

I took the brick apart and the main electrolytic cap had yellow stuff oozing out of the positive leg, so that had to be replaced. We did so, but it didn't change anything: the console still power cycled. The brick appeared to be fine at this point: both output voltages of 5v and 12v were present and stable and also the main cap read 382v.

It was time to open up the console itself and it was at this point that it became clear the problem is in here and not the power brick (although that main cap still had to be replaced nonetheless): have a look at this LAN chip ! Completely gone ! The failure must've been quite the show, because there was some arcing to the chassis of the RJ45 plug as well, clearly indicated by those holes in it ! WOW ! This opened up some new possibilities.

Not having this chip on hand and nothing to lose at this point anyway, we agreed to remove the shot chip and see if the console at least comes on without it. I took on this challenge myself and it was a nightmare to do: I'd say it took me around an hour to finally pull off the remains of that chip and clean the area ! The bastard wouldn't budge, no matter how much heat I pumped into it ! My buddy helped me out with the soldering iron while I worked the tweezers and the hot air gun, but it was useless: the ground plane simply wouldn't melt ! In the end I had no choice but to use a sharp knife to chip away at the black casing bit by bit until I exposed the metal beneath it. Then I used the largest hoof tip I had to apply a large blob of solder directly onto the metal and worked it back and forth until the remains of the chip eventually peeled off. I was skilled (or rather lucky ?) enough that no traces actually got damaged. L581 got a bit charred on one of the corners, but should still be good.

Sadly, our box behaves exactly the same, however there is a light at the end of the tunnel: as I was searching for possible solutions, I came across a thread of our very own where a chap describes a fairly similar issue, despite not mentioning exactly how his LAN chips looked like and whether they were physically destroyed as ours was, so it could be the console is simply refusing to boot without a LAN IC on there.....

The other two possibilities are that the blown IC also damaged the DC-DC converter it's attached to, OR killed something further down the data line, in which case the board is toast. We were both pretty tired after wrestling with the chip for so long, so we closed it back up for the time being with no other measurements. The IC apparently is a Realtek RTL8151GNM.

We'll go ahead and order some replacement chips to try it out anyway and see what happens...

Any schematics for an Xbox One out there ? Couldn't find any, at least not of the console....we're talking about Microsoft after all I keep finding schematics of the controllers, ironically enough

[Dannyx]

Re: Xbox One dead LAN IC

Just in case someone was curious about the outcome of this story: I got the chips from Ali, soldered one on, but the problem persisted: same boot-loop as before. I'm not sure if the chip was not soldered on properly or there's still some other fault going on. It IS slightly crooked - I suck at soldering QFNs in general... I also noticed the small coil next to the chip (which would indicate there's a power rail there), is not giving me any voltage at all, even in the brief moment the fan is spinning, so that in itself could be another issue - after all, the chip was completely blown when I got it, so it should come as no surprise there may be a ton of other defects.....anyway...it was worth a shot, but it's now gone to electronics heaven

[stj]

Re: Xbox One dead LAN IC

you should also check the network transformer - unless it uses a magjack.

[Dannyx]

Re: Xbox One dead LAN IC

you should also check the network transformer - unless it uses a magjack.

No network transformer that I can see, so it must be built into the RJ45 connector...

It's worth mentioning it DOES respond to the touch-key being pressed. White LED comes on on both the box and the brick, the hard disk comes on, the fan comes on, but there's no picture. It even ejects the CD if you press the eject button. After a few seconds, it doesn't just cut out and goes back to orange - it plays the "shutdown" jingle as well, so it's like a "proper" shutdown the console initiates and not a shutdown triggered by a short circuit or a failure that causes it to "die". It could be it's failing some internal self-test of sorts, if it even does such a thing to begin with. The LAN IC not getting power could be a reason...WHERE the power comes from is a whole other story. I see a coil next to it, but no idea what it's driven by, since there's no damn schematic

EDIT: just realized I was talking about some pictures in the first post, but forgot to add them, so here we go. This is the original chip....or what was left of it...

[stj]

Re: Xbox One dead LAN IC

nice!
that's a magjack, the transformer has arced and burned up.
probably from lightning.

you need to remove it, and check all the small resistors.
and the inductor.
everything in the area pretty much

[Dannyx]

Re: Xbox One dead LAN IC

Just stumbled upon this vid where the chap pretty much does it for me: towards the end, he removes the chip from the board entirely and he gets exactly the same result as we do: the console doesn't POST without the IC on there, so this pretty much confirms that either the chip is not on properly, or there is some other fault related to that area.....I realized now that I had no idea the jack itself can still cause issues by being there and maybe being shorted in a way that it doesn't allow the chip to run. I thought it's just a plug, a piece of metal and some pins, but it turns out there's actually some stuff inside of it which may still be dead...

[stj]

Re: Xbox One dead LAN IC

it contains several 1:1 isolation transformers and sometimes some ceramic caps and/or resistors.