Fairphone 5 - Unknown History, reboots and lock ups

Help Fairphone 5
1

Hello everyone. I’ve just joined the forums as I couldn’t find anything about this issue on here or online.

As a background I repair phones as a hobby. Sometimes I resell them, sometime I keep them but I figure it helps to keep devices out of landfill and I enjoy it.

I recently purchased a Fairphone 4 and a Fairphone 5. The Fairphone 4 was a simple fix, new screen and then an FRP bypass and it’s good as new.

The Fairphone 5 however is giving me issues. It was stated as having a software fault that caused it to freeze occasionally, needing a reboot. However I’m leaning towards it being a hardware fault.

I’ve been able to reproduce the issue regularly. It happened on an older FP Android 14 release it shipped with, I updated to the latest version and it happened again. I then unlocked the bootloader, wiped the device (fastboot -w) and used the manual OS install method from Fairphone. The issue still occurs. I now have LineageOS installed, rooted to see if I can capture more data about the issue. The device has rebooted once and locked up under Lineage once already.

The issue is twofold. The most often occurrence is that will just reboot itself without warning. The second seems to be when the device is sleeping. It will refuse to do anything, the screen will not turn on, no haptic feedback can be felt and it will not power on with any combination of physical button presses. The only resolution is to remove the battery.

The only log file in /data/anr I’ve been able to pull was relating to the battery state changing. Funnily enough it said battery state changed to 20%, however the device was reading 45%. According to the battery info in the official Android 14 OS the battery is 100% health with 0 cycles. Either the phone was brand new (it is in flawless condition), or could there be something wrong with the battery? Physically it looks fine.

I have fully disassembled the phone to see if there were any tell tale signs or water damage but didn’t find any. The only thing I noted was that the ribbon connecting the “Top Unit” to the main board had a strange discoloration, almost like it had been exposed to heat.

I am currently keeping the device on charge, powered on to see if the issue occurs while it has an external power source. The other thing I will try is to disconnect this ribbon to the top unit and see if the issue re-occurs.

Any other ideas? Obviously I could start replacing parts immediately but I don’t want to start throwing money at this device if it’s a lost cause.

2

Can you measure voltage with or without battery/of the battery?

This setting should vanish after certain conditions
(Will search and add…)

This happens because we have removable batteries and once a user replaces battery with a new one, SW can’t refresh previous battery consumption data.
So to avoid display of inaccurate data, If certain conditions are met then Battery health will disappear if the battery has been removed and re installed ( even if removing and installing the same old battery)

However

A certain set of conditions need to be met for the status to be removed from the device.
One such criteria is that user can remove and install battery within the first 7 days after activating the phone to allow user to install a SIM and battery health will not be affected.

so I agree that info seems odd unless the FP5 is less than 7 days old

Maybe someone in your area has a FP5 to test the battery? E.g. an Angel fairphoneangel

3

Thanks for the reply. The phone does not seem to have pass through power, so will not power without a battery. However the voltage is being read by the system as 4.03v so fairly inline with the 70% battery status I currently have. I’ll grab my multimeter and confirm that the true voltage is consistent with what the system is reporting later.

As I went to check that, the phone froze with the screen on at the home screen. Again only a battery pull would resolve it.

I’ve now removed the whole top unit, including the cameras to see if there was any merit to my suspicion after noticing the discolouration on the ribbon cable. The phone soon after has gone into the screen off, no response issue so I suppose the issue doesn’t lie with any of those parts!

The battery is the only lead I have at the moment, after these few crashes I’ll see if I can pull anymore logs. (No logs found)

This may be because I completely wiped the device and reinstalled the OS. Maybe it sees it as new?

Nearest one to me is over 100 miles away (UK) so I’m out of luck there.

The last message I caught before the latest crash was a WLAN one. So I’ve turned off WiFi and left the device plugged into my PC running logcat. If/when it next crashes I should get an idea what the phone was trying to do before it happened. Current uptime is 19 minutes, so I’ve not broken any records yet.

4

A slight update. It appears these are two separate, unrelated hardware issues.

Whilst connected and reading the logcat I realised the device has gone into it’s screen off, unresponsive state. However the log was still producing lines and responding to the button press. It seems as if the device at random cannot power on the screen.

The reboot issue, I’m going to assume is the WiFi issue that has been documented on this forum.

My only resolution, considering that a complete wipe and different ROM hasn’t resolved anything would be to use a different main board. (I have a feeling this device was a faulty return, going off how good the condition is)

As that’s not a feasible part to replace I feel the best way to proceed will be to sell the parts and keep the main board for testing any future devices.

5

Do you tried reconnecting the display cable? Maybe it just got a bit loose.

6

Yeah I’ve had the phone completely disassembled, twice!

It’s a shame, I wanted to use this as my primary phone because it feels so premium and I got a great price on it. I’ve just finished up taking photos of all the components to list on eBay. At least the phone can help other people keep theirs running.