Nexus 5 Stuck on 4 Dots + E: failed to mount /cache (Invalid Argument)

[simonpaps]

Please help,
I have a vanilla nexus 5 on 6.0.1 hammerhead OS and when i woke up this morning it would not start and would be stuck on the 4 dots screen. I tried to factory reset and clearing the cache through the system recovery screen but it keeps saying E: failed to mount /cache (Invalid arugment). I dont even care about saving my data anymore, I just want my phone back.

 

[lunatic59]

Can you get it into fastboot? Press and hold power & vol. down. You might have to reflash the firmware.

 

[simonpaps]

I've tried reflashing (using minimal adb and fastboot command and entering "fastboot oem unlock" and then "fastboot flash recovery [then i added the flash image i downloaded from the website]" ) to 6.0.1 hammerhead which i found here https://developers.google.com/android/nexus/images#instructions.
Thanks for your help!

 

[jj14x]

and then "fastboot flash recovery [then i added the flash image i downloaded from the website]" )

I assume you did it correctly, and just didn't type out the exact command here
(If you extracted and then flashed the individual images from the image file you downloaded, you'd have flashed each .img file)

Anyway, did you flash the cache partition?
And did flashing the image fix your issue?

 

[simonpaps]

for that i put "fastboot flash recovery" then i just click and dragged the downloaded file from the google website into cmd which put the file address into cmd. the file i downloaded from that website was the mob30h 6.0.1 file and it only came with the one file so there was only one file to flash which was a .tgz file ext.

I dont think i flashed the cache partition as i dont know what that is lol
no unfortunately it did not fix the issue, after it was done i tried to boot my phone and the google screen showed up with a lock symbol in the bottom center. Then it went straight to the dead android lying on its back with a red triangle warning sign coming out of its bowels (pretty brutal if you ask me)

 

[lunatic59]

If @simonpaps followed the instructions, he probably used the flash-all.bat script, which would have included the cache partition.

 

[lunatic59]

for that i put "fastboot flash recovery" then i just click and dragged the downloaded file from the google website into cmd which put the file address into cmd. the file i downloaded from that website was the mob30h 6.0.1 file and it only came with the one file so there was only one file to flash which was a .tgz file ext.

I dont think i flashed the cache partition as i dont know what that is lol
no unfortunately it did not fix the issue, after it was done i tried to boot my phone and the google screen showed up with a lock symbol in the bottom center. Then it went straight to the dead android lying on its back with a red triangle warning sign coming out of its bowels (pretty brutal if you ask me)

Ah, okay, so you didn't follow the instructions. It's a bit more involved than that. I put a tutorial together for the Nexus 6 but it's the same process for the N5, just the files are different.

Read through this and if you have any questions, it's better to ask first.

 

[simonpaps]

Like most people you help i unfortunately did not follow the instructions properly as i was confused but I will try your guide you linked and update you on my progress! thanks again!

 

[simonpaps]

I cant seem to locate the flash-all.bat file and im a little confused by step/chapter 7. When i type cd sham and then press tab nothing happens except my computer makes that weird trumpet noise

 

[Brian706]

If the flash-all.bat was used, I would try doing each img manually. There is notorious issues with the flash-all script. I never once had it work on my N5 and always had to flash manually.

 

[simonpaps]

i dont have any .img files from the firmware, all i got from that google driver website was a .tgz file which i opened with 7-zip and extracted a .tar file

 

[Brian706]

i dont have any .img files from the firmware, all i got from that google driver website was a .tgz file which i opened with 7-zip and extracted a .tar file

Extract the .tar file as well then you should see all the files you need!

And just a note, there will be a zip file in with the other files. You will need to extract the individual images from that as well if you are going to flash them manually.

 

[simonpaps]

what is the command to flash individual images? and how many are there for 6.0.1 hammerhead mob30h
nevermind i figured out that part, when i tried to flashboot system and user data it says "target reported max download size of 1073741824 bytes
erasing 'userdata'...
FAILED (remote: failed to erase partition)

 

[Brian706]

Edit:
Were you actually able to unlock the bootloader? Because since the latest versions of Android, as a security measure, in a booted up and functioning device you are required to unlock the hidden developer options menu and then tick the option to allow oem unlocking before you can unlock the bootloader. So all of this may be a waste of time if your bootloader isn't already unlocked because without a functioning device, you cannot unlock the bootloader which is the first step before you can flash any images.
----------------------------------------------------------------------------------------------

To save some typing, I'm going to copy/paste the command info from jhawkkw's guide and also customize the command to be tailored to your specific images so that you can copy/paste if you'd like.

For this, I will assume you grabbed the latest factory image: 6.0.1 (MOB30H) and you will be flashing 6 images (7 if you also do the userdata image; optional but might as well). Make sure that all the images are in the directory you are issuing commands from, they should all be in the same directory and not within any other folders. The same directory you set fastboot up in.

You should be able to issue the commands in this order, and make sure each one is "finished" before issuing the next commands. The system image will take awhile to install so just be patient on that one especially. Also note that the reboot-bootloader command will reboot your phone into the bootloader again, so you will see the display go dark when you issue that command, then return to the bootloader screen.

fastboot erase boot
fastboot erase cache
fastboot erase recovery
fastboot erase system
fastboot flash bootloader bootloader-hammerhead-hhz20f.img
fastboot reboot-bootloader
fastboot flash radio radio-hammerhead-m8974a-2.0.50.2.29.img
fastboot reboot-bootloader
fastboot flash system system.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img
fastboot flash cache cache.img
fastboot erase userdata
fastboot flash userdata userdata.img
fastboot reboot

 

[lunatic59]

I cant seem to locate the flash-all.bat file and im a little confused by step/chapter 7. When i type cd sham and then press tab nothing happens except my computer makes that weird trumpet noise

As I said, the file names will be different. Under no circumstanses try and flash a firmware that starts with "sham" (for shamu ... codename for the Nexus 6). Yours should start with hammerhead, so you'd type

cd hamm

and then press the tab key for it to populate the rest of the folder name.

 

[Brian706]

FAILED (remote: failed to erase partition)

Yep, that's what I was worried about. You have a locked bootloader so you are unable to execute the fastboot commands.

 

[simonpaps]

Edit:
Were you actually able to unlock the bootloader? Because since the latest versions of Android, as a security measure, in a booted up and functioning device you are required to unlock the hidden developer options menu and then tick the option to allow oem unlocking before you can unlock the bootloader. So all of this may be a waste of time if your bootloader isn't already unlocked because without a functioning device, you cannot unlock the bootloader which is the first step before you can flash any images.
----------------------------------------------------------------------------------------------

To save some typing, I'm going to copy/paste the command info from jhawkkw's guide and also customize the command to be tailored to your specific images so that you can copy/paste if you'd like.

For this, I will assume you grabbed the latest factory image: 6.0.1 (MOB30H) and you will be flashing 6 images (7 if you also do the userdata image; optional but might as well). Make sure that all the images are in the directory you are issuing commands from, they should all be in the same directory and not within any other folders. The same directory you set fastboot up in.

You should be able to issue the commands in this order, and make sure each one is "finished" before issuing the next commands. The system image will take awhile to install so just be patient on that one especially. Also note that the reboot-bootloader command will reboot your phone into the bootloader again, so you will see the display go dark when you issue that command, then return to the bootloader screen.

fastboot erase boot
fastboot erase cache
fastboot erase recovery
fastboot erase system
fastboot flash bootloader bootloader-hammerhead-hhz20f.img
fastboot reboot-bootloader
fastboot flash radio radio-hammerhead-m8974a-2.0.50.2.29.img
fastboot reboot-bootloader
fastboot flash system system.img
fastboot flash boot boot.img
fastboot flash recovery recovery.img
fastboot flash cache cache.img
fastboot erase userdata
fastboot flash userdata userdata.img
fastboot reboot

I'm not entirely sure if I did unlock the bootloader options before, in bootloader it allows me to unlock the oem and the lock state says unlocked. when i tried to input "fastboot erase boot" it says "FAILED (remote: failed to erase partition) Also when i first did it, i did not know there was a specific order i had to flash so i did the boot.img first not the bootloader.img and it said OKAY but after that everything else said FAILED

 

[simonpaps]

Yep, that's what I was worried about. You have a locked bootloader so you are unable to execute the fastboot commands.

Is there anything I can do at this point?
I was able to erase all my stuff but cant flash bootloader

 

[Brian706]

Okay, there is something else you can try, that is a new thing Google is doing; and I forgot about it until now. They are now offering full factory images in the form of an ota to sideload and this works regardless of locked or unlocked bootloader state!

Download this file: https://dl.google.com/dl/android/aosp/hammerhead-ota-mob30h-672f59e1.zip

Put the zip (and leave it zipped) in your adb/fastboot directory on your pc.

put the phone into recovery mode. From the bootloader menu press the volume keys until you see recovery, then press the power button to select it. Then when in recovery mode hold the power button and tap volume up. A menu should appear. Select the option to "Apply update from ADB".

Then issue the command: adb sideload hammerhead-ota-mob30h-672f59e1.zip

When it's done, choose the option to reboot system now.
Source: https://developers.google.com/android/nexus/ota


These are an equivalent of flashing a factory image. I will warn you now, that there is a chance you have a hardware failure. That could be why the commands aren't working even with an unlocked bootloader, and why the device suddenly wouldn't boot anymore. If this works, great! If not, it's probably a hardware failure and nothing any software will be able to fix.

 

[Brian706]

Okay,

I just noticed the image you posted of your command prompt and I know why it failed to write the bootloader.

The command should be exactly: fastboot flash bootloader bootloader-hammerhead-hhz20f.img

According to your image, the command you input was: fastboot flash bootloader c:\users\simon\desktop\phone\hammerhead-mob30h\bootloader-hammerhead-hhz20f.img

And the image files need to be directly in the "Minimal ADB and Fastboot" folder on your pc.

 

[simonpaps]

Okay, there is something else you can try, that is a new thing Google is doing; and I forgot about it until now. They are now offering full factory images in the form of an ota to sideload and this works regardless of locked or unlocked bootloader state!

Download this file: https://dl.google.com/dl/android/aosp/hammerhead-ota-mob30h-672f59e1.zip

Put the zip (and leave it zipped) in your adb/fastboot directory on your pc.

put the phone into recovery mode. From the bootloader menu press the volume keys until you see recovery, then press the power button to select it. Then when in recovery mode hold the power button and tap volume up. A menu should appear. Select the option to "Apply update from ADB".

Then issue the command: adb sideload hammerhead-ota-mob30h-672f59e1.zip

When it's done, choose the option to reboot system now.
Source: https://developers.google.com/android/nexus/ota


These are an equivalent of flashing a factory image. I will warn you now, that there is a chance you have a hardware failure. That could be why the commands aren't working even with an unlocked bootloader, and why the device suddenly wouldn't boot anymore. If this works, great! If not, it's probably a hardware failure and nothing any software will be able to fix.

The error message i got on my phone is E:/ failed to mount /cache. Does that mean its dead and I have to get a new phone?

 

[Brian706]

The error message i got on my phone is E:/ failed to mount /cache. Does that mean its dead and I have to get a new phone?

It's possible, unfortunately...

But you can try the factory images again and make sure you saved all the images to the correct folder on your pc and make sure the commands you are issuing are exactly as I typed them in THIS POST.


Starting now, I will be mobile for the rest of the night, so getting to in depth is difficult, but I think I've gotten most of that covered already in my last few posts.

 

[simonpaps]

I tried that again and got the FAILED (remote: flash write failure)
Thanks for all your help, both of you I really appreciate it but I think its time to call it.
Last thing if you dont mind, im from ontario, canada could you recommend me a good affordable phone with android OS? I really liked Google's phones but seeing how this can happen has made me less of a believer.
Thanks again everyone, even though it didn't fix youre all still heros in my eyes!

 

[jj14x]

Call Google and tell them what's happening "failed to mount cache" - I've heard of several instances where Google replaced the device. If that doesn't work, try calling LG - no harm in trying.
Here in the US, most credit cards offer free 1 year extended warranty if the purchase was made using their credit card. (one card I have even offers 2 years extension). Check to see if you have that option available.

Hardware failure can happen to any device - whether it is a Nexus, or Apple Device, or Samsung device etc. Personally, I wouldn't write off a future Nexus device just because of this one instance.

The Nexus 6p is an excellent device (though, keep in mind that the new Nexus devices should be out this fall - can't wait that long - I know - sorry). Or, for the first time in a very long time, I'd even recommend a Samsung Galaxy S7 - really good reviews of that device (and it has a really good camera on it) - touchwiz is tolerable this time around.

 

[lunatic59]

I tried that again and got the FAILED (remote: flash write failure)
Thanks for all your help, both of you I really appreciate it but I think its time to call it.
Last thing if you dont mind, im from ontario, canada could you recommend me a good affordable phone with android OS? I really liked Google's phones but seeing how this can happen has made me less of a believer.
Thanks again everyone, even though it didn't fix youre all still heros in my eyes!

I just want to be perfectly clear here.

The firmware file you downloaded ... first, did you verify the CD5 checksum to make sure the download wasn't corrupt? (it was in my instructions ... i get the impression you don't like to follow instructions exactly.)

Next you unzipped the file into the same directory where fastboot.exe resides?

Next, you decompressed the .tgz file that contained all the partition images (all those files @Brian706 listed that ended in .img)

Next, you put your phone into fastboot mode and were able to connect successfully with

fastboot devices

Finally, you typed exactly

fastboot flash bootloader bootloader-hammerhead-hhz20f.img

I see you started with saying you were using 6.0 already and if I recall there is one extra step to unlock the bootloader which requires you to check a setting under developer options, but since you couldn't boot into android to do that, it may be the problem why you can't flash ... because your bootloader isn't unlocked yet, even though fastboot says it is.

If you really want a new phone (and who doesn't?) you'll have to define "affordable" for us. I like the Motorola line right now and some of them are extremely reasonable. The thing is that when you ask for recommendations, everyone will have an opinion that might not be exactly what you might like, so don't take our word for it and before you buy see if you can get one in your hands to see if it "feels" right.