Disabling WiFI/Bluetooth by hardware [ From Raspberry Pi Zero W to 3B+ ]

Translations:

• Español

Index:

1. Intro.
2. CYW/BCM43438 schematics.
3. X-ray images and WLBGA ball map (colored).
4. Images showing what to remove and extra.
5. Raspberry Pi Zero 2 W shield information.
6. Pliers to remove the SMD inductor and video.
7. Check by terminal if WiFi and Bluetooth are disconnected.
8. [NEW] Scheme with examples to disable WiFi and Bluetooth from different layers.

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Intro:

One of the biggest problems are that Raspberry Pi do not show the schematics of the wireless. See this example: https://datasheets.raspberrypi.com/rpizero/raspberry-pi-zero-w-reduced-schematics.pdf

Thanks that we got access to a X-ray picture of the wireless chip, I tried to figure out some of the circuits. Not easy because that PCB is multilayer. So I just figured out some of them.

The best news are that RPi Zero w and RPi Zero 2 W wireless chip still in the same position, is not rotated and in both boards we should remove exactly the same SMD component. Cool!, isn't it? 🙂

I didn't end up removing VDD becasuse I can't see well the all layers and to me seems like VDD comes from another PCB layer under the chip.

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CYW/BCM43438 schematics:

Basic schematics showing were we are going to get rid of the SMD inductor.

Documentation source: (https://www.cypress.com/file/298076/download)

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X-ray images and WLBGA ball map (colored):

🟠 Orange big dot made as position reference.

Here we have the X-ray image and normal one to let you know the actual position.

X-ray image by @Vilas1979

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Images showing what to remove and extra:

Image showing what to remove to disable WiFi/Bluetooth by removing the inductor that goes to the pin SR_VLX:

Information about SR_VLX:

VDD and GND still connected into the board but chip is not able to work without the inductor. But don't worry:

💡 As a simile: Having a car with 1 of 3 ABS/brakes cable broken. The engine will start, but the ECU will detect that the ABS is not reachable. So is impossible to get connected to it, transmit any data and use that component.

EXTRA: If you got the case that you would like just to remove the WiFi, just remove this component:

Raspberry Pi Zero 2 W metal shield information:

This is the metal shield that contains the wireless chip. You should remove it, in order to access to the SMD components:

You can use:

To remove the whole shield:

1. Heat gun
2. Hair dryer

To break a part of the shield:

1. Dremel
2. Sand paper

Once you have removed it you will see this (marked in red, the component to be removed):

Remove SMD inductor

Easy: with pliers:

Video showing how to remove it with pliers:

📺 Video of the process:

• Video by @SeedSigner

Text tutorial just using desoldering iron:

• Get soldering iron quite warm. Put the soldering iron on top of each extremes (first one, and then the other) of the SMD and push a bit to one side.

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Check by terminal if WiFi and Bluetooth are disconnected.

WiFi

Once you boot the system, open Terminal and type:

• ip addr

If there is not wlan0, WiFi is disabled by hardware.

Bluetooth

Open Terminal and type:

• bluetoothctl

If bluetoothctl do not open or seems to be frozen, is good signal... But if open type:

• scan on

If you can see values (Probably not), write me back.

Enjoy!

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NEW scheme with examples to disable WiFi and Bluetooth from different layers.

As a note: If a new kernel is compiled without the WiFi or Bluetooth modules, as well as disabling certain components, it is not necessary to use any of the commands shown above.

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If you like it you can support me: On-Chain ⛓️ or ⚡️ Lightning network

License: CC BY 4.0