I think you know about it as least as much as I do.
I would not use the continuity tester at all since the Voltage of the continuity tester on some multimeters can provide up to 9V that’s quite a lot for chips that are designed to handle 3.3V or below.
Try measuring the Voltage between the 3 pins of the switches while the Phone is switched on an then see if something changes between the Pins depending on the position of the switch.
But that’s just my option.
I do hope you know more than me :). Otherwise both of us do not know much about the hardware of the phone.
Good point. I really do not know how my multimeter does measure continuity or resistance.
I’d really need some competent guidance here by someone who knows how to diagnose the problem.
@dos, @guido.gunther any chance someone could give me instructions?
So you are determined that you are not going to contact Purism support?
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I can confirm that I studied the schematics and that kill switches really do switching on the hardware level which is not programmable. Some signal paths from them to actual power cut are more complex than others but it is quite complex task to distribute power without higher lost. So the power is distributed mostly on variable battery level 3.4 to 4.3 V and converted to required voltages in place of its use. There is wired/diodes/resistors logic to combine switches together for GPS switch off and rescue boot combination function. I am not sure if this passive logic does not draw more power than some advanced LVTTL chip. As for the components I can imagine some scenarios when some components can be powered by some I/O pin which is not cut. But most of connections to i.MX8M goes through level shifters so even that possibility is eliminated and I consider driving mobile baseband or WiFi through GPIO pin to the level that it can communicate as impossible. So even if some signal is omitted it cannot result in unsafe state.
What is a shame that at least components placement is not provided. Self-repair and experimenting with GPS antenna and other stuff is quite difficult without it and for these really paranoiac even possibility to check for tamper is much more difficult. It is even more shame that previous iterations was highlighted to provide X-rays scans etc… But world is not perfect… and I have knowledge at least to have some remote idea about amount of work to reach actual state… in i.mx1 days we have started from really chip level with zero lines of other code and with only self compiled GNU tools and serial bootstrap code and building own JTAG only later when already made Linux kernel and RTEMS system boot on the device.
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Why you is calling to @guido.gunther ? Guido asked you a question that you never answered him above.
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I suspect I found its origin. To me it looks the same as some pin that is positioned in the plastic frame:
This is what I decided to do to avoid the danger that might be my continuity tester to the Librem5. I made this little chart:
I measured the voltage between the middle pin of the switch and the other two pins. The table shows that in position 1 (up if the phone is upright) the voltage between the upper two pins is 0V and the voltage between the lower two pins 2.25V. If I move the switch to position 2 (down) the voltage between the upper two pins becomes 2.25V and the voltage between the lower two pins becomes 0V.
To me this looks like the switch is mechanically working and therefor probably not the cause of the misfunctioning of the camera kill switch.
I looked through the manual of my multimeter and the only information I found about the continuity tester is that the current used is smaller than 0.3mA - no information about the used voltage/signal. I guess I’ll have to measure it when I’ll have another multimeter around…
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Hi @ChriChri, I tend to agree with you the switch seems to be behaving as expected. And with your measurements, that also suggests that at least the outer 2 pins of the switch are connected to PCB otherwise you would not see the voltages behave like this.
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This.
Hi @ChriChri, that pogo pin is still troubling me, not that I think it’s got anything to do with the hardware killswitch of the camera, but if I were you I’d still be interested what kind of connection it was providing within the phone. From the pictures you’ve posted It looks like is below one of the m.2 cards either mobile or wifi and is connecting that card to the base board below.
Maybe someone with access to the complete design information on the Librem5 can validate how many times that pin is used in the phones design. I’m pretty sure I found one of these set into the plastic frame where the gps module is placed. My guess is that I found a “spare part” that has been left unintentionally inside the phone.
Or maybe that’s something that Purism support could help you with that does not involve sending the phone back. 
Thanks again for that warning!
I came around to measuring the voltage on mine and found it uses ~2.5V. But without knowing it had been the best decision not to try it …
BTW: My Librem5 is said to be returned from Purism this week. I’m curious whether they found some explanation for the not working kill switch and the pin I found…
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It’s back or better: it’s exchanged.
Diagnosis is (if I understood that right, @nicole.faerber?) : microswitch for camera was bad and a problem with the wifi card.
The latter I didn’t notice. Wifi always worked like I had expected.
Anyway, huge thanks to everybody for their support and to Purism to solve the problems.
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Riddle solved.
Taking apart my Librem5 (the one I had received from Librem5 in exchange for the one on which the camera hks didn’t work) I found this after a while in my workspace without knowing where it came from:
Looking around a bit I found the solution. Took the following picture from the article on how to take apart the Librem5. The green marks show the location of these pins:
The following pictures show
- left picture, green mark: where the pins are located in the middle plastic frame beside the screws below the two modules (in this example the wifi/bluetooth module)
- middle picture, red arrow: the connection pad on the mein pcb it connects to with its bottom side
- right picture, red arrow: the connection pad on the module it connects to on the upper side. This rim would be touched by a screw would the module be fixed at with a screw directly I guess.
When the plastic frame is removed these pins tend to fall out of the frame like in this picture:
They can easily be put back in their holes and probably will stick there if fixed with some glue.
I’d suggest to add this to the article by @david.hamner, because at the moment it is the resource everybody is pointing to when needing a manual on how to disassemble the phone.
No worries anymore , @Manuel.
PS: So funny, look where I found the pin when I first wondered where it’d belong.
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I find the camera switces off after toggling the kill switch, but it doesn’t turn on again with the switch. A restart is needed for that to happen.
Is this a known problem? If so, is there a remedy?
No, it’s not a known problem. Could you attempt that and then send the output of the command sudo dmesg from the terminal?
I think it might have solved itself. I’ll keep you posted when it re-occurs.