I'm no expert, but my guess would be some sort of hardware failure. That device is past its expiration date, so to speak, and maybe the seller was starting to experience issues too.

if you do manage to un-brick it, I would not rely on that device for anything important - if it is hardware failure, this will almost certainly happen again.

    allobious If the device had been lightly used, flashing a new OS might have exposed weakness in the flash storage (it's a lot of writing all at once).

      Probably9857 de0u
      Thank you for the reply.
      So you are suggesting it's probably hardware aging ?
      Now that you are mentioning a low of writing at once, i did transfer 2 movies from my PC to the internal storage of the device, about 5 GB of data in total.
      I transferred the same exact movies on my OnePlus 7T that i have been using as my personal device for 4 years. No problems though.

      • de0u replied to this.

        allobious So you are suggesting it's probably hardware aging ?

        It may well be.

        allobious i did transfer 2 movies from my PC to the internal storage of the device, about 5 GB of data in total.
        I transferred the same exact movies on my OnePlus 7T that i have been using as my personal device for 4 years. No problems though.

        There isn't a rule that transferring exactly X GB to a phone that is exactly Y years old will cause the flash storage to quit!

        The suggestion is that if an old device is about to quit then storing a lot of data to it might trigger the problem.

          de0u
          Good to know for future devices.
          I unchecked the OEM unlocking when i installed the Graphene OS.
          So i guess there is no way to unlock the boot loader right ?

          • de0u replied to this.

            allobious Try holding the power and volume-down buttons together for a long time (more than a minute). Maybe you can get into Recovery and factory-reset the device, at which point it might work for a while.

            Meanwhile, the project's position on the device since October 2023 is:

            Pixel 4, Pixel 4 XL and Pixel 4a are end-of-life and shouldn't be used anymore due to lack of security patches for firmware and drivers.

            I held the power + volume down for 3 minutes. Fast boot showed up for 10 sec, then restarted into fast boot again for 3 minutes.
            When i released it it managed to boot into graphene os for 5 seconds i saw my wallpaper and i could interact with my device.
            Then it started bootlooping again.

            • de0u replied to this.

              allobious I held the power + volume down for 3 minutes. Fast boot showed up for 10 sec, then restarted into fast boot again for 3 minutes.

              I would expect that holding power and volume-down for a while would bring up Fastboot, then releasing the buttons and using the volume and start buttons would get you into Recovery.

              If the device instead restarts itself I would suspect a hardware issue, which could likely be confirmed at a repair shop.

                I think the important thing here is that the device is insecure.

                Even if you bring it back to life, it will still be insecure.

                  de0u
                  I left it to charge over night. When i woke up this morning, it has booted up successfully.
                  I enabled OEM unlocking in case i need to unlock the bootloader.
                  Any recommendations/suggestions on what to do know?
                  The 5GB movies are still in the device. Do i delete them or let them be ?
                  Blastoidea
                  Thank you for the reminder. As @Probably9857 suggested, i will not rely on this device anymore, for anything important.
                  It was just an experiment, i wanted to get a glimpse of Graphene OS, without paying 500 + Euros for
                  a new device.

                  I am considering getting the Pixel 8, do you have any experience with this model? Does it overhear on Graphene OS?
                  1 thing that stood out to me, was the idle activity of the device is almost 0. My OnePlus 7T will lose 10% of its battery in 8 hours just in idle. Pixel 4a on Graphene OS, just 2%.

                  Thank you all for the support.
                  Again, if you have any other recommendations,
                  i would be more than happy to hear them.

                  • de0u replied to this.

                    allobious I left it to charge over night. When i woke up this morning, it has booted up successfully.
                    I enabled OEM unlocking in case i need to unlock the bootloader.
                    Any recommendations/suggestions on what to do [now]?
                    The 5GB movies are still in the device. Do i delete them or let them be ?

                    If the problem was only that the battery was low (though that seems a little surprising), neither deleting the videos nor keeping them should be problematic.