Endless boot process after I turned on "QuickBoot"


  • Right now, the only tipp to avoid this is: Turn off QuickBoot! The Software team is investigating the issue and will hopefully be able to include a fix in an update soon.
  • If you are stuck in the endless boot process you can try the following:
  • Wait and see. (For many this is in fact not endless, but resolved itself over night.)
    • Keep your phone plugged in and an eye on it for the first hour or so to make sure it doesn’t overheat. Otherwise abandon the wait and see strategy.
  • Take out the battery, take out the SIM card(s) and SD card, let the phone cool down
    • Put back only the battery and try to boot
    • If it boots normally now switch off QuickBoot, turn off the phone and put the cards back in
  • If nothing else works try to make a hard reset. (:warning: this will delete all your data)
  • If the hard reset doesn’t work either you can recover your phone via adb or Fastboot. If you don’t know how ask for help here.

##Original Post:

To make the alarm work even when the phone is switched off (just like the FP1), I followed the workaround from another thread (this one) and turned on “QuickBoot” in the developer options. The result, unfortunately, was the extreme opposite: The FP2 got stuck in some kind of endless booting loop (until finally the battery was empty). During this loop the Fairphone booting screens were shown, but after the “LOADING” screen the phone didn’t start but (very shortly) the “App X of XXX ist optimized” message was shown - before the booting screens started again. On each loop this message showed a different app number - without chronological order.

Any idea what to do anyone?

Can you go to Recovery Mode?
There you can reset the system cache and if that doesn’t help make a hard reset ( :warning: deletes everything) .

Deleting the system cache didn’t make any difference. Oh dear, my boyfriend will be very angry if I have to spend another weekend to set up the FP2 all over again. This really sucks… :cold_sweat: Any other ideas before I delete everything? I might just leave it in it’s boot circle over night. Maybe there really is something to optimize. It can’t really get worse.

Sure, it’s worth a try.

Thank god… the just wait and sleep strategy worked. The phone made it out of the boot loop by itself. And curious as I am I switched QuickBoot off and on again - it didn’t bring another boot loop but didn’t really speed up the boot time either. So, I guess I’d rather put the phoe in flight mode if I want to use the alarm.


I’m glad it worked out, but still there must be something wrong with your phone if you can’t properly use quickboot mode.
Maybe an App you installed tries to contercept quickboot?

PS: Another good way to keep the phone while sleeping is the battery saver function in the advanced battery settings.

Maybe. But with about 200 apps on my phone I won’t try out which one is the troublemaker…

This also happened to me after I activated “QuickBoot”. Endless reboots and the only thing appearing for less than a second was the app optimization. Strangely, the phone was reachable via “adb shell” while doing this loop and I could even use su there, get logfiles etc.
I suspected that the installation of privileged F-Droid (which I had tried but failed before the last reboot) was failing: https://f-droid.org/forums/topic/installed-as-privileged-now-phone-stuck-at-boot-logo/ but also deleting the folder in “priv-apps” did not help.
I don’t know enough about Android to find the exact problem and also waiting did not help but the phone got quite warm (there are many messages about temperatures in the logs :confused:) So I now did a hard reset via recovery. Fun fact: user data is gone, but things like su and silencing the camera survive it :slightly_smiling:
If someone is curious about this, I can provide the “adb logcat” output via pm or email.

Fun fact: user data is gone, but things like su and silencing the camera survive it

That’s good to know, though not very surprising: my understanding of factory reset is that it only wipes or cleans the /data partition.
Which also means: For any mess we make in the /system partition, a factory reset won’t help :grinning:

Same thing happened to me – and unfortunately the “wait and sleep” strategy didn’t work for me.


  • Encryption enabled
  • Quickboot enabled
  • two SIM cards and a microSDXC card inserted
  • German language
  • FP2 not rooted or flashed

What I did:

  1. Switched on my FP2 (well, obviously not really, due to Quickboot).
  2. Removed the battery
  3. Exchanged one SIM card (for a new one that is not yet activated before Monday).
  4. Inserted the battery again
  5. Switched on my FP2 again

What happened first:

  • I was asked for my encryption key.
  • On top of this, I was asked (in the foreground) for my first SIM card’s PIN and afterwards for my second SIM card’s PIN.
  • After providing both SIM card PINs I was able to provide the encryption key.

What happened then (in a loop):

  1. The blue “Fairphone” banner and afterwards the white “Fairphone / Start a movement” banner appeared.
  2. The white screen with the blinking text “Loading…” appeared.
  3. The text stopped to blink.
  4. A “popup” on background appeared, stating “App X of Y is optimized” (“App X von Y wird optimiert”)
  5. (Goto 1)

I noticed that the numbers X and Y both changed. At least I saw X being 7 and 15 and Y being 175 and 202. I assume that 202 is the total number of installed apps, whereas 175 is the total number of enabled apps (as I disabled most Google apps).

I tried:

  • wiping the cache partition (in Recovery Mode)
  • removing the SIM cards / microSDXC card
  • the “wait and sleep” strategy (for 6 hours)

But the problem persisted. As I’m going on vacation today (which makes this even more annoying), I won’t be able to share further insights before Tuesday, but I won’t give up trying (because a hard reset currently isn’t an option for me).

By the way, is there any way to backup the /data partition before the hard reset (note: device not rooted)?

Hi @clsbln, do you have developer options and USB debugging enabled? Then you can still try “adb shell” and poke around to get your data. And if you need root to access what you want, in principle you can still root now - I also flashed the boot loader while my FP2 had the reboot problem. This will give you “su” in the adb shell.

Since today, my FP2 cannot boot anymore.
It seems a bit like this issue with FP1: Fairphone does not boot anymore

When I switch the phone on, I first get the black screen with the Fairphone and Android logo, then the blue screen with the Fairphone logo, then the light grey one with the “loading…” text.
After a few minutes, I get a message box for a very short time (cannot read it or take a photo). Then the procedure starts again with the blue screen and the light grey one.
I can only stop this by removing the battery.

During this the phone gets quite wam (CPU is running…).
I have fast boot mode enabled.

Same behaviour with 2 SIMs, 1 SIM, no SIM and no SD card.

Maybe related: In the recent days I experienced some (2-3) sudden reboots during a telephone call.

Hi Jakob!

Hm that doesn’t sound good. Have you tried to dis- and reassemble the battery? Otherwise, I only have the following ideas:

Disclaimer: Only try the following, if you don’t mind losing all your data. Otherwise, my only suggestion would be to contact support (scroll down to the bottom of the site).

Do you have a backup of your data? If so or if you don’t mind loosing the data, you could try a hard reset, i.e. wipe data/factory and cache in the recovery menu (see step 2 in these instructions). Just to be sure, I mention it again: All your data will be lost after this!

If this doesn’t work, there is also a topic about a soft bricked FP2 (your phone is not “bricked” but at least also screwed up). The solution there is to flash a fresh copy (a zip file) of the OS via recovery, which will also erase all your data! However, I’m not familiar with the procedure there and can’t estimate how complicated this is.

Btw what do you mean by that? If you power on your phone with the power button, then the phone is in the mode of booting the OS. In this mode, there is no possibility for fastboot to be enabled. Fastboot mode is accessed after turning off the phone by pressing and holding the Volume Down and the power button for a few seconds. Note: in this mode you’ll only see a Fairphone logo and nothing else will happen.

Yes I disassembled the battery several times because this was the only way to interrupt the loading/boot mechanism.
I did not know about how to use the fastboot mode. I have always used the power button.

I will try the “wait & sleep” strategy.

In fastboot mode, the phone itself does nothing. This mode is only good for controlling the phone from the PC (via USB connection), for example to flash images or format partitions.

Hey guys, I also was forced to chose the harsh alternative: hard reset (admittedly I wasn’t patient enough for sleep’n’wait option). However, strangely it did not occur after first time booting with quickboot. After I set it on quickboot, I tried it - and it just worked perfectly! But then the other morning it did not start again, symptoms as you’ve described. I am curios how that could be resolved, the quickboot is still kinda appealing to me although it made me set up the thingy all over again :stuck_out_tongue:

I think we need to differentiate between Fastboot and Quickboot as I believe it brought some confusion into this threat.
Fastboot, as @tphysm described, is an interface to use with your pc, most often used to make serious changes to the operating system or replacing it completely.

Quickboot is a feature that can be enabled in the settings of the FP2 that will shorten the boot sequence, since it doesn’t switch off the phone completely but rather sets it to standby. This is for now the only way to make an alarm work, while the phone is switched off, apparently because the timers etc. are still running…

Good news: I was able to solve the problem by giving my FP2 more time (> 24 h) to escape the boot loop (right after wiping the cache partition once more, to be sure).

To me it seems like

  1. Android has to “optimise” each app after the phone has not been powered off properly,
  2. the order in which the apps are optimised is random and
  3. the process crashes after each app optimisation.

Then it would take as much time as it requires for each app to be randomly chosen to be the first app to be optimised.

And to clarify: The QuickBoot mode we’re talking about can be enabled only once the Android developer options have been activated. The developer menu then contains the item “Enable QuickBoot mode” which is described as follows: Put device into QuickBoot mode instead of normal power off.

In theory, I could imagine that this problem does not only affect phones with enabled QuickBoot mode but more generally any FP2 that hasn’t been powered off properly.


Hi clsbn,

I took my FP2 off the charger after being in “the death loop” for around 24h.

My question: How can i wipe the cache partition?

@Moritz: Thanks for clarification. Yes, I was talking about the Quickboot feature.

Power off the phone. Go to recovery mode by holding Volume Up and power button at the same time for a few seconds till the phone vibrates. Wait for android image and then for the menu. Navigate down by using Volume buttons to “wipe cache partition” and confirm with the power button. Then you can reboot the system (first entry in the recovrey).

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