Hardware Debugging faulty BCM4356 / orange screen / boot loop

[acidcoolxxx]

That can't be true. That would mean that all Switches with a broken BCM chip are unfixable.

They are fixable but with a donorboard that is alredy programmed.

I found this:
Programming OTP Memory on an Android or x86 Platform This section outlines the procedure to program OTP memory on an Android or x86 platform. Required Hardware:■1× CYW4354, CYW4356, or BCM4358 – this is the DUT.■1× Android or x86 platform to which the DUT is connected.Required Software:■Cypress SDIO MFG driver package: contains driver files for the CYW4354, CYW4356, and BCM4358. This driver package is typically provided by Cypress.■OTP.bin file: contains the information that is going to be programmed into device OTP memory. The OTP.bin file is typically provided by Cypress.OTP Memory Programming Steps:1.For platforms running the Android OS, load the DHD driver with MFG firmware:adb shellifconfig wlan0 downecho "/system/vendor/firmware/fw_bcmdhd_mfg.bin" > /sys/module/bcmdhd/parameters/firmware_pathifconfig wlan0 upNote: After the driver successfully loads, the OTP memory can be programmed.Note: Follow the normal procedures for installing the WLAN driver on x86 platforms running Linux or Windows. Information on the normal procedures are outside the scope of this document.2.Run the following command to check the contents of the OTP memory:> wl cisdump

So what if we check the content of an working one and try to copy the content like in the tutorial above?

 

[GrimDim]

That can't be true. That would mean that all Switches with a broken BCM chip are unfixable.

I don't know man, certainly all Switches with broken NAND are actually unfixable ¯\_(ツ)_/¯

One of the threads that reports this: https://gbatemp.net/threads/replace-ic-wifi-bcm4356xkubg-with-the-new-one.544895/

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So what if we check the content of an working one and try to copy the content like in the tutorial above?

That would be pretty cool! What is your source for this?

 

[acidcoolxxx]

[QUOTE="


That would be pretty cool! What is your source for this?[/QUOTE]

https://www.cypress.com/file/298136/download

I try a post on XDA forum maybe they can help us out.

 

[ds34]

The ZedLabz replacement chips come preflashed...

 

[linuxares]

Do you guys have some reader for the chip? Maybe possible to dump the info of it?
@SciresM (sorry I know you hate to be tagged) do you happen to know if the software of that chip is dumped?

 

[ds34]

Do you guys have some reader for the chip? Maybe possible to dump the info of it?
@SciresM (sorry I know you hate to be tagged) do you happen to know if the software of that chip is dumped?

Well, according to ZedLabz we don't have to flash it manually.
Do you think the chip is married to the board like with iPhones and their Touch ID/IR scanner scam?

 

[linuxares]

Well, according to ZedLabz we don't have to flash it manually.
Do you think the chip is married to the board like with iPhones and their Touch ID/IR scanner scam?

It's possible. That's why I ask for SciresM. The chance is high since the drivers might not be open for some reason. Why Linux nor Android can recognize it, the wifi that is.

Some broadcom cards for example needs proprietary drivers on Linux to get them to run. Then again, it doesn't answer why Linux distros works with wifi that have working chips. It's possible that is something stupid like encryption or such to limit a security hole or something in those lines.

 

[ds34]

Why does BT work then?

 

[linuxares]

Why does BT work then?

They might no be encrypted or such. As I said, I have no idea. Just shooting ideas out of my butt.

 

[acidcoolxxx]

The ZedLabz replacement chips come preflashed...

Thats where i get my chip from and still nothing.

 

[ds34]

Someone on the ReSwitched Discord server told me that the switch flashes the chip everytime it boots

 

[GrimDim]

Someone on the ReSwitched Discord server told me that the switch flashes the chip everytime it boots

Maybe for parts of it, but if Nintendo makes use of the one-time programmable memory that can only be flashed once obviously. It's optional though so maybe they don't use it, was just an idea I had.

 

[ds34]

So it has otp and "normal" memory?

 

[acidcoolxxx]

The safest way to verify, that the Chip is programed. We need to read the content of the OTP memory. I already posted the tutorial for that, but my switch is disassabled at the moment. If we only have 0x00 here we know its not programmed. Otherwise if there are values we can copy paste and try our luck.

 

[TariqSoftDev]

They do not use any sort of custom firmware for these IC's, it is connected over I2C/UART and that is used to configure on boot/interact.

On that note; if two people have the same issue due to a failure of this IC; have you checked to see if any other parts have failed before or after due to this?, that may be a good thing to do.

hence may explain android/linux still working since it won't always be as picky as HOS or something like such as it's looking for something in a very specific way unlike android/linux would.

 

[GrimDim]

They do not use any sort of custom firmware for these IC's, it is connected over I2C/UART and that is used to configure on boot/interact.

Hmm I see, too bad that could have explained some stuff.

On that note; if two people have the same issue due to a failure of this IC; have you checked to see if any other parts have failed before or after due to this?, that may be a good thing to do.

Hmm, how/what would you check? I can't seem to find anything else that's amiss, except for the wifi not working in Linux.
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I mean I guess it is presumed failure of the IC, no way of knowing for sure since we only have hints to go off on.

hence may explain android/linux still working since it won't always be as picky as HOS or something like such as it's looking for something in a very specific way unlike android/linux would.

This has been my thinking so far, which is why I was hunting for a patch to disable wifi check in HOS, but I don't think anyone has made one.

 

[GrimDim]

So I did another replacement of the BCM4356, this time from a donor board, and indeed the switch is still not booting, nothing changed. Pretty clueless as to what to try next

 

[ds34]

You mean it's stuck on the second logo, right?

 

[acidcoolxxx]

Mine does that.

 

[ds34]

Mine too, but WiFi and Bluetooth are both not working