Hardware Debugging faulty BCM4356 / orange screen / boot loop

[randy_w]

so you cna buy preprogrammed chips? i gues those are extracted from broken maonboards?

Yes, they are taken from switch motherboards. Both models are available (bcm4356 and cyw4356). If you want to buy replacements, make sure to order the same model your switch comes with as they are not cross compatible.

 

[slimmy182]

Hello guys,

i have some time so i try go back to this issue. After some research i found something to work with.

it is possible to dump the OTP.
https://www.infineon.com/dgdl/Infin...110_globe_en_all_integration-application_note

On Page17 the procces of programming the chip using android.
You need the Manufacture Firmware.
I got this find here: https://github.com/MoKee/android_vendor_lge_d851/blob/mkl/proprietary/etc/firmware/fw_bcmdhd_mfg.bin

this allows you to dump the OTP from a working WiFI chip. "wl cisdump"
with the command "> wl ciswrite OTP.bin" you can write to it.

I downloaded already the AndroidOS for the Switch. And try this today, wish me luck

As I understand it from reading up on, the chips have some pre-programed data specific to switches but they are the same for all models, and so it needs to come off of a dead switch. Though there is also data that the switch loads onto the chip each boot, I came across a project that says it will extract said data from the ofw system software; https://github.com/perillamint/nx-fwextract

A gentle reflow will likely fix mine, presuming that it stops working again, cuz there is definitely nothing wring with the actual chip. It just started working normally while I had it in my lap, poking around android recovery console. It may have gotten a little hot, or it may have gotten bumped in just the right way, idk. I expect it will fail again in time though, possibly as soon as it cools down again, heh. I'll just put it on top of my computer for now, to try and keep it cozy...

Any news in reprogram this IC?

 

[Acru]

Any news in reprogram this IC?

I haven't done any more on anyway. Mine hasn't failed again yet, as I feared it would, though I leave it docked 99% of the time and am gentle with it otherwise.

 

[slimmy182]

This is my story:
My switch WiFi/BT IC has failed, then I replaced with one purchased on AliExpress. Now WiFi it’s working good but BT does not, can’t connect to anything. Usinig Linux L4T distro both WiFi and BT are working good, It does detect and connect to joycon and network. This point me to a FW problem and not hardware related issues.

This is why I'm looking for any hint in reprogram this chip.

This is what CTCaer said after inspecting my Linux dmesg log: “you got the wrong chip BRCM4354A2 where switch one is BRCM4356A3 4356 is basically 4354 with different fuses but anyway. you need to solder the right chip or patch the bt firmware in the btm sysmodule grab BCM4356A2.hcd from /lib/firmware that’s what you need to replace it with. if you want to check what happens in l4t with hos fw, you can update it and then rename BCM4356A3.hcd to BCM4356A2.hcd and reboot it will probably throw errors in dmesg. you will need to create exefs patches for the relevant sysmodule that means that everytime it gets updated, you will need to create new ones now there’s an easier way to do that custom atmo loader. you will need to edit loader sysmodule and when it sees and tries to load the bt sysmodule, search the firmware and then patch it with the correct one you will need to search the size of it also and patch that too”.

"
[ 6.570208] Bluetooth: hci0: BCM: chip id 101

[ 6.570462] Bluetooth: hci0: BCM: features 0x2f

[ 6.571795] Bluetooth: hci0: BCM4354A2

[ 6.571801] Bluetooth: hci0: BCM4356A2 (001.003.015) build 0000

[ 6.585376] bluetooth hci0: Direct firmware load for brcm/BCM4356A2.hcd failed with error -2

[ 6.585393] bluetooth hci0: Falling back to user helper

[ 6.789688] Bluetooth: hci0: BCM: Patch brcm/BCM4356A2.hcd not found
"

That’s it. They sold as the right chip, taking these chips and printing the code of the right one on them even if they’re not actually the same.

@acidcoolxxx @Acru

 

[Acru]

This is why I'm looking for any hint in reprogram this chip.

[...]you need to solder the right chip or patch the bt firmware in the btm sysmodule grab BCM4356A2.hcd from /lib/firmware that’s what you need to replace it with

I expect what CTCaer said is correct, and I had a peek at the datasheet, the chips are one-time programmable.

You are out of luck if the OTP data is different than what you need. Technically you could maybe overwrite over the data on the chip in just the right way to make use of unused write space on the chip to make it work, but would require detailed hacker knowledge and you would have to write a custom file, in addition to having a chip programmer to put it on the chip, and messing up would likely kill the chip. That is assuming there is some program memory on the chip and not just a register or two of fuses, in which case you could only set fuses that remain unset,

The other two options, replacing the chip again or modding the switch's firmware, are advised, though the latter might be detectable and get the console banned? And as CTCaer said, it would need to be re-patched with every system update. IDK, not my area of knowledge.

Another option might be getting a 3rd party usb bluetooth adapter? A Mayflash NS Lite supposedly can talk to joycons and can pretend to be a pro controller to the switch, though you wouldn't be able to power up with the home button, is slow to connect, and of course there would be a dongle hanging off your switch in handheld mode. I use one with a Xbox One controller in docked mode meself.

 

[Whoops9934]

Alright folks good news: The brand new replacement chips work, no need to pull and reball ones off old Switch MOBOs.

I just put two brand new CYW4356-es into a V2 and an OLED. On both boards WiFi started working immediately. However the catch is that Joycon Bluetooth painings need to be refreshed before the previously paired Joycons can work again. I did this by using the Sync button on the joycons. You can also try deleting pairings from System menu.

That's it, Cheers!

 

[k28]

Alright folks good news: The brand new replacement chips work, no need to pull and reball ones off old Switch MOBOs.

I just put two brand new CYW4356-es into a V2 and an OLED. On both boards WiFi started working immediately. However the catch is that Joycon Bluetooth painings need to be refreshed before the previously paired Joycons can work again. I did this by using the Sync button on the joycons. You can also try deleting pairings from System menu.

That's it, Cheers!

where did you buy them?

 

[Whoops9934]

where did you buy them?

Aliexpress, I tried posting the link but newbies apparently can't.

I don't think it actually matters where you get them from, the issue I've seen people in this thread and on youtube dealt with was BT seemingly not working so I mostly posted to clarify the part that you're supposed to clear existing BT pairings for the new chip to start working.