What does the process of physically removing the wifi/bluetooth module look like for a Raspberry Pi 4? How hard it is for a beginner & for someone experienced with soldering? And how likely it is to damage some neighbouring component?

I don't care to save the module for re-use later on, just want to get it off even if that means damaging it.

This is for an air-gapped device, so physically unavailable hardware is much better than hardware disabled by software. I read this answer on a similar question but the one of RPi4 looks bigger, not sure how it looks under that metal shield. Couldn't find a guide on the same.

Evaluating RPi4 over other models which lack WiFi/Bluetooth capabilities purely on the basis of performance. CPU even though is only a little better, but memory seems to be a lot faster than any other models.

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    @Milliways So everyone who has ever done anything had the equipment for it beforehand? – Ashish Kumar - Ashfame Jul 24 '20 at 0:06
  • It seems unlikely that you'll find a "tutorial" on this :) The old phrase "Just do it" comes to mind. A few days ago I might have suggested that you consider a device like the "pocket beagle" - but my short experience suggests it sucks. – Seamus Jul 24 '20 at 0:24
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    If you try it and it goes wrong your experiment will have cost USD$50 as you'll need a new RPi. If the WiFi chip is SMD use a sharp Xacto knife to cut the pins close to the chip and leave it mounted otherwise. If it's a BGA chip you'll need to use a hot air gun. – Dougie Jul 24 '20 at 7:02
  • Thanks Dougie! As per cypress.com/file/348636/download it seems to be 140-ball WLBGA I am going to attempt Dmitry's short-circuit method below. Thanks Seamus! – Ashish Kumar - Ashfame Jul 24 '20 at 10:03
  • Before you go nuts attacking your Pi have you tried putting the Pi in a metal enclosure? That might be enough to block any wireless signals. As has been mentioned you will be lucky to find a tutorial specifically on the process of removing the Wi-Fi/Bluetooth module. Having a look it appears to be all surface mount components. So any tutorial covering the removal of those would be a starting point. – Darth Vader Jul 24 '20 at 12:45

If you want to physically disable Wifi/BT, the easiest way is to disconnect the antenna, or short the antenna output to ground via a 1nF capacitor.

enter image description here

Removing the WiFi/BT module is trivial with the right equipment (heat up the board and lift the shield and the IC up with a vacuum pen), but without a schematic I would not give you any guarantees that the rest of the Pi will work once the WiFi chip is gone. And even if the schematic is released, it would be quite a task to analyse it and create a modified device tree for the kernel to correctly understand the new hardware configuration.

  • I was trying hard to find that antenna on RPi 4, was about to ask you if you are sure the image is right :) – Ashish Kumar - Ashfame Jul 24 '20 at 8:26
  • This is 2-fold problem, as this being an open source project, I am not just doing it for myself but also asking others to do it as well. So whatever is the easiest and gets the job done with certainty is preferred. But how can removing a component without physically damaging nearby components even affect the rest of the board? – Ashish Kumar - Ashfame Jul 24 '20 at 8:28
  • Hopefully it gets clear with the right picture. I bet cutting that trace with an exacto knife is by far the easiest way. And yes, removing components can affect the rest of the board, electronic is not really like Lego but rather a bunch of loops in which current is flowing, and removing parts breaks those loops, so the current has to stop or go elsewhere. – Dmitry Grigoryev Jul 24 '20 at 8:33
  • OK, I trust you to know this a lot better than I do. So cutting with an exacto knife or shorting antenna output seems like 2 easy choices. In your screenshot, are you red arrows pointing towards those blobs of solder or the path? – Ashish Kumar - Ashfame Jul 24 '20 at 8:36
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    Thanks a lot for your guidance! I will circle back in a couple of weeks when I would have received my order & attempt to do this :) – Ashish Kumar - Ashfame Jul 24 '20 at 9:59

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