FP4 USB to PC connection does not work at all

I recently discovered, that USB C to audio stopped working - using LineageOS 20.

Now I realized, USB to PC stopped working as well - even when booting in to fastboot mode, it is no longer possible to connect to the device because it will not be recognized any longer.

Also enabling ADB in LinageOS recovery does not work. When I try to connect the device this way, it will not even try to talk to the PC.

The only thing which is usable is USB-OTG, e.g. for USB sticks.

And yes, I tried different cables, ports etc. - other smartphones work just fine with the same cables at the same PC.

So I can not restore the device to the original “Fairphone OS” and I can not connect the device to transfer data via USB.

Any hints?

Edit: I already did a factory reset and reinstalled the latest LineageOS 20 version (using the recovery and a ZIP file I copied over first, since connecting using fastboot does not work any longer). But USB still does not work to connect to a PC - neither for file transfer, nor fastboot.

I’d have guessed broken USB port on the phone. But if I understand you correctly then USB-OTG still works with the phone? Might still be worth trying to change the USB port and see what happens. On the FP4 this is a separate part, so the effort required should be minimal. Of course you’d have to get access to a spare part one way or another. Switching ports with another FP4 would be one option. That would also help determine if something else is broken.

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Might be a contact issue. In the good old FP2 times the recommendation was always to disassemble and assemble back the phone or at least the relevant areas.
For the OTG vs. other data we would have to check which data lines are used in the connector and in its connection to the phone. That might be an indication what exactly is broken.

Btw, I think you could have continued in your original topic instead of opening a new one with your additional findings. Maybe they can be put together.

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The original topic was about using USB C audio adapter where I did not realize that USB does not work in general and not just for audio.

Yes OTG works, charging also works.

When looking a the USB C pinout I don’t see any special connection which is used for OTG only and could explain why charging and OTG works but nothing else. And as far I know, OTG only means that the device will act as a host and provide power supply to the connected device but there will not be any special data lines needed for this.

Anyway, I ordered a USB plug replacement and will give it a try. However I wonder how this happens - mechanically there is not indication at all that anything is broken and the inside of the plug looks absolutely flawless under a magnification glass.

Agreeing with @Martin_Anderseck and will close the first topic to avoid further duplication.

You could just amend the subject to include both.


I was not aware of that. Thanks for closing the first topic.

I got a new USB port and replaced that part.

As expected: no change. Connecting a PC to USB does only charge the device and neither fastboot nor ADB work. So I can not even restore the original operating system since this requires fastboot connections to work, which is not the case. I did not expect anything else, but the money was well spent, so I can be sure my original expectation that the main module is broken is correct.

I’ll contact the support as well - but if they ask for money to replace the main module because I installed LineageOS, I won’t do this and see this as a lesson learned.

Oh my… and again the support asks for a proof of purchase! My device is registered for the extended warranty online - using the IMEI and serial number of the device! The same IMEI I entered when I contacted the support.

Very annoying when you want help as quick as poss.

I suppose the IMEI and warranty may define the device but not the ‘original owner’.

You could sell or gift the phone and the next owner would be asked the same.

Also I imagine at the early stage of request it’s done by a bot, so no intelligence or empathy there.

AI ~ Should be DI (Dumb Intelligence) or NRIAA (Not Really Intelligent At All )

So it’s AA (Auto Answer)

You’ll get there :slight_smile:

I have the same issue. OTG works but not file transfers to computer. Also no connection to Android Auto. I had changed the USB board/plug but that did not change anything. Nor did any of the options proposed by the Fairphone support. And I have this is issue running Android 12 provided by Fairphone. They want me to send in the phone for repair except that I need a replacement first since I can’t afford to be without a phone.

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Thanks for your report on this. At least I know that I am not the only one with this issue and it is probably caused by some problem in the device itself and not by changing to LineageOS.

Well - about sending the device in: you don’t have any alternative. It’s the only way how they will handle that since there is no obligation for Fairphone to give you another device right away. This will only be provided if you don’t purchase the device but only rent them using their subscription model. At least they promise to send a replacement within 48 hours if needed.

In my case I purchased another smartphone after I realized that replacing the USB port did not solve the problem. I expect that I will have to send the device in as well and wanted to be prepared as I also need my smartphone on a daily basis, e.g. for 2-factor-authentication, bank accounts etc. - it is a good idea to have a spare device available anyway, since things can happen.

@JoKa91400 @askaaron

Noting this topic is suffixed [lineageos] I am wondering if Fairphone support are clear that you are not using the the default OS as support is limited to that.

i.e. You have to have Fairphone OS [Android 12] installed to benefit from official support.

Failing that they will/may ask their physical support ‘workers’ [Cordon] to wipe your phone and install A12 before they look at any software or hardware issues.

I already told the support very clearly that I did install LineageOS in the past and that I can’t revert that to FairphoneOS since USB connections to the PC including fastboot don’t work any longer. And since I already did a factory reset to make sure that this is not just a software issue, I am totally fine with getting the phone wiped as long as this is fixed without asking me for money for a new main module.

I think you are OK there. There was a charge for re-installing the FOS, maybe some 20 to 30 €

Well - it seems to take a while.

I contacted support, they told me to do try obvious things like using another cable, use another computer, try factory reset. Then I told the support that I already did all that and that I want to send in the device for repair.

Now I am waiting for another response by the support where to send it and what information to supply with the package.

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After dealing with the UPS delivery guys (they claimed to deliver it, but never showed up even I was at home all day) I got the phone back. According to the service, the main module was replaced - so nothing I could have done my own.

So far the original problem is fixed. I’ll see how long this will last.

Just after turning the phone on it already offered me an update to software version SP2G.B.079 which claims to fix issues with the search bar in the launcher, display colors, 4G/WiFi call settings and AptX for bluetooth. Of course still on Android 12 - but better than nothing.

But now I am reluctant to install LineageOS 20 again since I can’t be sure that this won’t cause the same issues after a while. Are there any known cases with LineageOS causing the USB port to malfunction?

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