[Seeking help] Power mod flashing red

[VariablePwn]

Hello all!

I was working on a client's Wii U where they asked me to modify it with the "Unlimited 5v mod" for the rear usb cables.
The request was to follow this setup, where the positive terminal of the tantalum capacitor was connected to the two smd capacitors.
Link to images

I did this, and because of the requested tight turnaround, put the Wii U back together (rookie mistake), and plugged it in to test, only for it to start flashing red.
After apologising for the failure to deliver, the client said they understood, and that we can work on getting it working again.

By some random coincidence (and my ignorance), I didn't know that the Wii U doesn't provide USB power in standby, so after leaving it unplugged from mains and leaving a usb charging cable (with a little LED on the end) in, when I attempted to boot it up, it was a solid red! SUCCESS!
...or so I thought. Leaving it in for longer than a moment would have it go back to flashing.

After trialling a few things, I realised that the process to achieve "solid red" was as follows:
1. Unplug the power cable from the Wii U.
2. Insert USB charging cable with LED into either back usb slot.
3. Wait a minute or longer
4. Plug in Wii U power
5. *IMMEDIATELY* press the power button on the console.

This would provide a semi-reliable method of powering on the console, and successfully getting to the Wii U Plaza screen (extra thankful, since the client is running CBHC).
At this point, the Original two-wire mod has been removed, and replaced with a direct solder to the USB slot pins (see images).
The tantalum capacitor (C656) has been removed (which only slightly lengthens the time to press the power button), and also replaced with a Wurth electrolytic capacitor of equivalent value (and correct orientation!).

At this point, I am super stumped. I've checked all the components surround the rear USB ports, and they're all outputting ~5.15v.
It could be U23/U28, but I honestly barely know what they are, so I have no definitive means to check them.
Also the fact that the USB cable helping discharge something is my theory that there might be a voltage leak somewhere, but that's just me spitballing.
Additionally, my Wii U powers up no problems with the power supply, so it's not that. Though I do have another one somewhere that I could try, but honestly I don't think that's it.

If anyone could provide some insight or guidance, it would be super muchly appreciated!

 

[Siktah]

Got any pics of your soldering work?

EDIT: Whoops didn't see text links.

The only thing I suggest is reverse your work and see if that removes the fault. What solder and flux are you using?

 

[VariablePwn]

Thanks for replying!
I have reversed pretty much everything, and no dice. The good news is that if the Wii U is left unpowered for a time, and then plugged in, the red standby light will stay solid for a time, but eventually it will start flashing again.

I'm using a good quality Weller-branded 60/40 solder (with 2% flux) and some flux rosin that works really well. So doubtful it's either of those.

 

[V10lator]

At first it sounded like you produced a short or something (for the future: Try using magnet wire instead of normal one: Way more simple to solder) but the pictures look good and you reverted the mod already, so it can't be that.

On the other side https://gbatemp.net/threads/ultimat...reset-black-screen-after-stuck-update.642339/ also says a blinking red light is a short, so grab your magnifying glass and your multimeter and double check there is none. Sometimes the flux causes a micro drop of solder to quirt to some nearby but completely unrelated part, causing shorts there, for example.

//EDIT: Lastly I would suggest to not do the 1A solder bridge mod but the original mod you intended. Simply cause the 1A mod still shares this one A between the two USB ports, so when using two devices it's less than 1A / device. Also there are HDDs peaking over 1A. Anyway, whatever mod you choose do it only after the red blinking issue had been fixed. For now we stay in the unmodded / reverted state until the root has been identified.

//EDIT²: If all things are lost / you can't find a short at nearby components you could also try to completely remove this cap:

You have the first Wii U PCB revision in front of you, following revisions don't have that cap anymore anyway. Also we remove it (for the front USB ports) when installing a NAND-AID, so it's really not needed. Still I would do this as a last resort only and it might not help at all, my guess is just that maybe you somehow damaged it while soldering to it (this cap sits between 5V and GND, so it's a possible candidate for a short).

 

[Siktah]

The good news is that if the Wii U is left unpowered for a time, and then plugged in, the red standby light will stay solid for a time, but eventually it will start flashing again.

That's not a viable fix/solution at all. And neither is bridging the pads on the USB socket itself.

The SMD cap (C57) appears to have copped some physical damage - doesn't seem like enough to break functionality but still - looks like soldering iron has dented and scraped across.

You mentioned you have other WiiUs? I suggest you replace the customers one with one of yours (either modded or not) as it's not their fault you can't repair it yet. Make them whole before you spend hours/days/weeks down a rabbithole.

 

[SDIO]

Did you make sure, you didn't connect the disc drive cable the wrong way? Does this happen without the cable for the drive connected?
Else search the whole board for flakes of solder and give it a gentle brush

 

[VariablePwn]

Thank you everyone for your assistance.
I've tried a few things so far: removing both the two-wire, and the usb-bridge connection.
I have tried flux and heat (330°C) on all pins to ensure good connection and cleaned with iso and a firm brush to move away any loose particulate, followed up with a toothbrush clean.

Following that, the Wii U still flashed red unfortunately.
I removed the tantalum to see if that made a difference, which didn't work either.
Here is a picture of the current work. (Please note: I've wired up some enamelled magnet wire, but they're only connected on one end. No errand bridging either, which I checked with a multimeter.
C57 seems fine, I just brushed some solder one it at one point, and took it off with braid; hence the markings.

And thanks for your advice @Siktah, in fact I always have an agreement with clients that if I cause any damage I'll compensate or replace their console. So if I don't get it fixed when the client picks up their other console this weekend, they have the option to leave with one of mine.

Post automatically merged: Feb 7, 2024

Did you make sure, you didn't connect the disc drive cable the wrong way? Does this happen without the cable for the drive connected?
Else search the whole board for flakes of solder and give it a gentle brush

Yeah, cable is in the correct orientation (extra tabs on drive side), and no dice.
Just gave the whole top-side of the board a hairdresser's special (wash, brush, and blow dry) and no luck either.

Tried removing the cap again, and still no luck

 

[SDIO]

Then measure the resistance on the output of all the buck converts. Maybe someone can give reference readings

 

[VariablePwn]

Then measure the resistance on the output of all the buck converts. Maybe someone can give reference readings

So I did two things: One, realise I didn't need to keep the dvd drive connected in order to check red light, so that was removed, and two, started measuring the resistances of the little black 5/6 pin chips (presuming they are the buck converters), and some of the resistances were in the kOhms, and were increasing when I was measuring them, but across the two, they seemed the same (could both be bad I guess).

HOWEVER! After checking the resistances, I plugged the console back in, and it's now solid... so I'll see how long it stays solid for, and we can go from there.

 

[SDIO]

Also if this happens without the console being turned off, it can't be the 5V, tha gets only tuned on later. Also the standby stuff only activates after the console was booted once after power loss. So it would be something on the 3V3 Standby rail, as that should be the only thing powered.

The Wii U (WUP 01) has 6 buck converters in pairs of two. You can see the pattern with the big plymer cap, the coil and the transistor / driver chip: https://gbatemp.net/threads/ultimat...creen-after-stuck-update.642339/post-10308257
There is one for 3V3 standby, 3V3 proper, 5V for USB, 1V5, 1V2 probably dram, 12V disc drive (not marked in the picture)

 

[VariablePwn]

Also if this happens without the console being turned off, it can't be the 5V, tha gets only tuned on later. Also the standby stuff only activates after the console was booted once after power loss. So it would be something on the 3V3 Standby rail, as that should be the only thing powered.

The Wii U (WUP 01) has 6 buck converters in pairs of two. You can see the pattern with the big plymer cap, the coil and the transistor / driver chip: https://gbatemp.net/threads/ultimat...creen-after-stuck-update.642339/post-10308257
There is one for 3V3 standby, 3V3 proper, 5V for USB, 1V5, 1V2 probably dram, 12V disc drive (not marked in the picture)

The solid red was a red herring... i pressed power and it did nothing. I'll check the converters, thank you for the diagram

Post automatically merged: Feb 8, 2024

So this is going to seem insane, but I checked the resistances and voltages of the 3.5 and 15v "when adapter in" sections by connecting to ground and other relevant points, and now the console seems to boot.
I've been doing on/off cycles every 5 minutes for about 30 minutes now, including plug-pulls, and it seems to be a stable red standby light.

I've also reconnected the "infinite power mod" (not the bridge one), and it's still going strong.
Absolutely no idea how or why, except maybe that something on either of those voltage areas needed to be grounded for some reason, but hey, it's (currently) working!
Wish me luck!

 

[Siktah]

Just checking how you went with this?