N900 reboot loop - any way to rescue data off eMMC?
 

First of all an apology if this is covered somewhere. I am currently on an overseas trip and while I have done some searching for possible solutions I haven't exhaustively done so.

My N900 started continuously rebooting (while it was charging off a car-charger during a road-trip. No explicit action such as installing or updating a program kicked this off). It starts the normal boot sequence (the 5-dot animation) but after a short while the sequence always stops on the second dot from the left (unsure if this is of significance) and the phone reboots.


I have re-flashed the OS using flasher-3.5 several times. Regardless, the phone's behaviour has not changed. I have not yet flashed the eMMC as I don't want to lose the data on that, if at all possible, hence this posting.

Is there a way to boot the kernel into a minimal rescue mode which would let me access the eMMC from a PC to backup the content?

Alternatively is there a rescue kernel or custom firmware I can flash onto it to the same effect?

So far I have not found any info on kernel boot parameters for the N900 or special rescue/recovery modes it can be booted into. I have also not found a detailed explanation of the command-line switches to the flasher tool (eg, what is 'cold flashing'?)

Any help much appreciated!

- Micha.
(V.glad now that he took another phone with him on this trip...)

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Yes turn of the phone and then plugin the usb-cable. The n900 should come up as a mass storage device. Also don't forget to view hidden files and directories.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Hi Arono,

I know the phone normally mounts itself as mass storage. Given my current boot problems and the fact that Windows has been failing to mount (or, indeed, recognise) the phone I was searching for an alternative way to access the eMMC as I thought the mass storage mode wasn't getting activated at all.

Your response prompted me to try again, in particular, using Linux, this time with more success. I was able to list the phone as a USB device and even (briefly) mount the phone's eMMC so it still seems to be working despite the booting issues.

Unfortunately I now also have the problem of a flat battery and have been unable to get the phone to charge it. I'll post again when I manage to get hold of a charged battery - which seems unlikely until I get back to the UK.

- Micha.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I see. You seem to have more problems with the phone than I did when mine was in a reboot-loop(got to the desktop). I could easily mount the phone in windows and linux without interruption. And I see no reason why the battery shouldn't load. I think you might even have to use your gurantee.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

An update:

Managed to get the battery charged using my N95 (and some creative fiddling). Copying the eMMC contents now - had to use RD mode as I couldn't get the phone recognised in normal mode.

Reflashed completed (eMMC & firmware; twice) and gotten it to boot in RD mode. Still in the same reboot loop in production mode.

Won't charge in RD mode (even though it says 'USB mode - charging only' when connected via USB).

I think it's a case for a warranty return when I'm back in the UK :(

But at least I have my data off it. Lesson learned: Buy a SD card and make regular backups to that!

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Update: Came back to the UK, discovered the Nokia Store on Regent street had closed. Pretty disappointing. Combined with Easter and the freepost pickup/return warranty service which Nokia runs, I only just got my phone back.
Or rather, a replacement. No indication of what was wrong with the old one.

At least the backup functionality seems to have worked, which is nice. But it doesn't back up everything (eg, contents of home directory, pictures taken, etc.) - so still need to manually back up various other bits and pieces to ensure no data loss.

Anyway, hopefully back to coding soon.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

hi,

i've got exactly the same issue... I tried reflashing several times but doesn't change annything.

Since it's my second N900 (the first one had a fix orange led light issue couldn't even flash it)

I'm really annoyed what's the probleme with this phone ?

Re: N900 reboot loop - any way to rescue data off eMMC?
 

You'll always get a certain percentage of bad items in any production run. We'd need a lot more statistics to see how many people have hardware problems compared to how many have none. Remember it's usually only people with problems who post on forums :) So I don't think there's anything inherently problematic with the N900.

Having said that, my first replacement from Nokia had a dodgy touchscreen which stopped working completely after only a day (looked like it was a refurbished phone and presumably it hadn't been fixed it properly). My second replacement looks to have been brand new and, so far at least, is working fine.
So in my experience Nokia's after-sales care is somewhat sub-optimal, but likely still better than a lot of other manufacturers.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I've got a hardware problem with my N900. The phone will not boot, just show the nokia logo for some seconds and die afterwards. The phone just was dead when I came back to it a couple of days ago, and never started ever since. I have images and videos on the phone I want to save before exchanging it from nokia. It flashes the rootfs nicelly so I hope it will be possible to access the EMMC in any way.

PLEASE!!.. :(

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Is there any update on the story ?
I too used a car charger to get my phone into this state. My reboot loop is like:

1.black screen-> 2.yellow light slowly blinks twice (like it were charging battery)-> 3. one really really short blink of green light -> 4. dim Nokia logo and dark background -> 5. running dots (like it was gonna launch the bootscreen) lasts maybe 4 seconds- > 6. black screen again for maybe 4~5 seconds

it would keep looping for who knows how long. However, I could still bootup if I try to hold down the power button for a few times in a loop at stage6.

The micro usb port has a weird behavior now. It would only prompt ONCE for selecting mass storage mode/pc suit mode when plugged. Subsequent unplug/plug of usb cable would only charge and display charging messages.

The loop starts again after I switch it off. The ONLY way to stop it is to take out the battery.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

@philsson - I used flasher3.5 to switch the phone into development mode, and I could then connect it to my (Linux) PC and copy the contents of the eMMC off it.

@htchang - The final update to my story was that it took 2 returns to Nokia to get a working N900. They never told me what was wrong with the original unit. Have you tried reflashing your phone? It sounds like yours isn't as badly broken as mine was. You might still have to resort to a warranty repair though.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

i just flashed the emmc and the rootfs today.. didnt help. it seemed like the phone "thinks" itself always in charging mode..

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Hi,

I had a similar problem while using my N900 with the in-car charger. I was using the N900 as a GPS and it failed half way through the journey with that well known dry-swallow noise and getting very hot indeed.
Luckly I could switch it on later on without loop-reboot but I've got another issue.
My keyboard started to mis-behave. The "upper-case" key, the letter "t", and left and right arrow keys no longer work. The letter "e" key while pressed produces "et". Is that "E.T." trying to phone home?:D
It feels like a joke but it is not funny at all!
I've tried to change this behaviour by trying different foreighn keyboards but still no joy. Changed the language, no joy. Flashed OS (thanks God the U key still behaves as U) but no joy.
The phone also "dies" at least once a day for no apparent reason, i.e., it swallows hard and deep and faints, going into deep sleep!
Any other suggestions appreciated. This is the first phone that dies on me so often and that I feel I cannot rely on in times of need.
I haven no guarantee as I've bought it in working order on ebay.
Thank you kindly.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I have exactly the same problem with my N900, I didn't use a car charger though. I've tried reflashing it and doesn't work.

I can get it out of the reloop only if i turn it on when connected to the wall charger.

Has anyone tried changing the battery?

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I remember that the reboot loop is a kernel problem. search on this forum for the official kernel and flash it with flasher3.5 maybe it will help without the need to flash the whole os.

It works for me

Re: N900 reboot loop - any way to rescue data off eMMC?
 

First off you don't need to flash your phone for this. You will need the flasher-3.5 program on a PC, Linux, or Mac. Then with the back cover off, and battery out, start to hold the u key on the keyboard, plug the battery in while keeping your finger on the u key (you shoudl only have to hold u down after plugging the battery in but just to be sure). Now plus the usb cable into the phone. It will show the nokia screen, with a little usb sign in the top right corner.

No in terminal (assumign linux or max) type:

flasher-3.5 --enable-rd-mode

for pc

flasher-3.5.exe --enable-rd-mode

This will enable rd mode on your phone. Unplug usb cable. Your phone will reboot, and shoud load all the way up. After it does, turn it off. Hold down the u key again, and plug in the uSB cable again. Now type in your terminal again:

flasher-3.5 --disable-rd-mode

for pc:

flasher-3.5.exe --disable-rd-mode

That will return your phone to normal operating mode.

As a curiosity have you already updated to PR1.2?

2d

Edit: If this was a kernel problem, you would not see the blinking dot process. It would go to the Nokia Screen, go blank, and then reboot continually. This is a seperate issue from that.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I have the same reboot secuence as mentioned here. .. problem is that there is no way of getting the phone into the usbmode. Cannot activate it. I press the u and the plug in the usb and the phone just boots to the loop... DAMN!!!!!

Re: N900 reboot loop - any way to rescue data off eMMC?
 

i have the boot looping problem too..

the phone boots normally at first but when the desktop starts loading, it restarted again and again.

so i tried enable rd mode, the boot screen shows some messages, one of it is

no initfs \o/

rd mode didnt work, loop still happen.

how do i fix this ?

Re: N900 reboot loop - any way to rescue data off eMMC?
 

I too have a crocked n900,

Works ok with a charged battery apart from it does not respond when a usb cable or wall charger are plugged in so cant charge or backup data (apart from bluetooth).

If i turn the phone off and plug any microusb lead into it it goes through the nokia screen with back light off and dots loading loop process.
Once i turn it back on it boots fine but cant charge or use as mass storage.

Any ideas?

Re: N900 reboot loop - any way to rescue data off eMMC?
 

Any ideas guys ??

sorry to be a pain i don't have my n900 at the moment, i am charging the n900 battery through my old n96,:(

Re: N900 reboot loop - any way to rescue data off eMMC?
 

hey plz, help me out.. i just bought a nokia n900..and installed mobile hotspot on it..coz it was not working i uninstalled it.. (possibly power kernel problem)..now my phone is not booting at all..it tries with NOKIA screen but then shuts down and again same repeats...plz smbdy help me.

Re: N900 reboot loop - any way to rescue data off eMMC?
 

bhupendra you probably fixed you problem now but if anyone else reads this, this is the exact thing that happened to me.. I uninstalled mobile hotspot and then tried to remove power kernel using app manager instead of the "deinstall poewr kernel" app and it screwed my phone. I got it working again following the wiki instructions but I only needed to download the pr1.3 image and flash the kernel from it with this command line:



flasher-3.5 -F RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin --flash-only=kernel -f -R

Re: N900 reboot loop - any way to rescue data off eMMC?
 

@cjard
same here , i uninstalled power kernel from app manager, and after next reboot. my mobile was gone!!!! reboot loop!!!

Re: N900 reboot loop - any way to rescue data off eMMC?
 

The kernel is an integral part of the software that runs your device. If you remove the kernel, the hardware has no way of communicating with the software. Consider it to be a bridge. If you burn that bridge, nothing comes across. That's why there is a "Remove Power Kernel" application that will remove the power kernel and re-instate the default Maemo kernel before applying the changes.

Don't just remove kernel-power from HAM / FAM, you WILL bork your device.