Question Wii U turns on but no video output – forgot C194 capacitor

[mems26]

Hi everyone,


I recently tried powering on my Wii U, but I get no signal at all—neither through HDMI nor analog output. The GamePad also fails to connect, even when I turn the console on using the GamePad's power button.


I realized afterward that I had tried to boot the system without the C194 capacitor installed. This happened because I had installed the Café Flex and incorrectly reconnected the 3.3V line to it, so the capacitor wasn't receiving power. I believe this capacitor was acting as a decoupling cap between 3.3V and ground, and its absence may have caused voltage instability during boot—possibly leading to issues with the NAND or eMMC, or preventing proper startup.


I've since put the capacitor back in place, but the console still doesn’t output any video and shows the same symptoms.


I'm still a beginner and would really appreciate any help or guidance.
Also, I'm not sure if I'm posting this in the right section—please feel free to let me know if I should move it.


By the way, I'm not very good at English and I'm using a translator, so I hope everything is clear.


Thanks!

 

[YveltalGriffin]

Hi! C194 is not required in any way. You're supposed to remove it when installing caféflex. Is this an untrimmed motherboard?

If you can, please share clear photos of the motherboard and explain what all you've done so far, including your softmod setup.

 

[mems26]

Thanks again for the quick reply — I really appreciate it!


Okay, I just realized something kind of stupid on my part...


I completely forgot that the Wii U actually needs the Wi-Fi module to boot. I really thought it could start up without it. Now I’m almost certain my module wasn’t connected properly — I think my soldering job was bad and I may have slightly melted the connector when attaching it to the Café Flex.


That would explain a lot. I’m going to try resoldering the Wi-Fi module properly and see if the console boots normally.


Just to give some context: the Wii U hasn’t been trimmed or softmodded yet. I was about to do that right after installing the Café Flex, and that’s exactly when the console stopped booting. So I really hope the issue was just the missing Wi-Fi module.


I’m attaching a few photos to show where I’m at. I’ll probably open a proper worklog soon.


Also, thanks again for all the amazing work you’ve done on the Wii U — from the guides to the Café Flex and all the PCBs. It’s really incredible and super helpful!

Edit: Oops, sorry about the message! I wrote it in English, but my browser automatically translated it into French!!!
Edit2: No worries, it’s in English now

 

[YveltalGriffin]

The console will boot to the home screen without the Wi-Fi module connected, but it will freeze when loading a game or entering the system settings menu.

It's unclear what exactly you've done to the mobo-- did you install and then remove a caféflex? The flex does not hold up to repeated reworks and I wouldn't recommend desoldering and then reusing it.

I'd focus on getting the motherboard back to a known good state. Resolder the SLC NAND onto its original footprint if you haven't already, and use a multimeter to verify that 3.3V isn't shorted to GND as a result of the rework near the NAND/eMMC vias.

If you melted the Wi-Fi module connector, I'm not sure what to suggest. It's a custom connector so there's no way to replace it, and a manual Wi-Fi relocation is much more challenging than installing caféflex. For future reference, you should never use hot air directly on the wireless module connectors. Instead, blast the underside of the motherboard with ~400C hot air and gently lift the connector with tweezers once the solder melts.

 

[mems26]

Thanks again for your help!


Just to clarify: I haven’t touched the NAND at all yet. As I mentioned earlier, the console was still completely unmodified — I only soldered the Café Flex to the motherboard, but I hadn't connected anything to it yet. I never moved the NAND or made any permanent changes.


The Wi-Fi connector got damaged when I tried to attach it to the flex. I had removed it earlier using hot air from the bottom side of the motherboard, as you suggested. But when I tried to solder it back onto the flex, I thought it wasn’t aligned properly and tried to reposition it — that’s when the connector melted.


That said, I’ve now wired the Wi-Fi module manually through the vias, and the soldering looks good. I get about 0.35 ohms of resistance on each connection, so I think continuity is solid. No visible damage either. (Just a note: in the photos, GND and 3.3V aren’t soldered yet.)


Also, I’ve just realized that I may have accidentally damaged C76 and C79 when installing the Café Flex — I likely overheated them with the hot air. When I desoldered them to check, they completely broke apart. I’ve marked them in the photo.


I don’t know what their values are, so I can’t replace them yet — but I suspect this could definitely be related to the boot issue. If you happen to know their specs, that would be a huge help.


Thanks again for your support!

Sorry for the photo quality, my microscope is really terrible ‍♂

Edit: The solder joints in the photos might look like they’re touching, but that’s just due to the poor photo quality. I’ve double-checked, and there are no shorts.

 

[CrashBash]

Merci encore pour la réponse rapide — je l’apprécie vraiment !


Ok, je viens de réaliser quelque chose d'assez stupide de ma part...


J'avais complètement oublié que la Wii U nécessitait le module Wi-Fi pour démarrer. Je pensais vraiment qu'elle pouvait démarrer sans. Maintenant, je suis presque sûr que mon module n'était pas correctement connecté : je pense que ma soudure était mal faite et que j'ai peut-être fait fondre légèrement le connecteur en le fixant au Café Flex.


Cela expliquerait beaucoup de choses. Je vais essayer de ressouder correctement le module Wi-Fi et voir si la console démarre normalement.


Juste pour donner un peu de contexte : la Wii U n'a pas encore été modifiée ni softmodifiée. J'allais le faire juste après avoir installé le Café Flex, et c'est exactement à ce moment-là que la console a cessé de démarrer. J'espère donc que le problème vient simplement du module Wi-Fi manquant.


Je joins quelques photos pour montrer l'état d'avancement. J'ouvrirai probablement bientôt un véritable journal de bord.


Merci également pour tout le travail incroyable que vous avez accompli sur la Wii U, des guides au Café Flex en passant par tous les circuits imprimés. C'est incroyable et super utile !


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Edit: Oops, sorry about the message! I wrote it in English, but my browser automatically translated it into French!!!

@mems26 Please go ahead and use the edit function on your post (bottom-right corner of the message) to change your message contents to be in English. We have a rule to use English when conversing as it's the language most common among our members.