I was trying, without success, to set up a simple shell alias (alias ls = '/usr/bin/gnu/ls --color=auto', in /etc/profile?). I knew it might need rebooting to activate, so I tried the phone’s Switch Off (which rebooted but didn’t activate), then “sudo shutdown now”, which apparently does nothing (is the n900’s shell a bit quirky, or do I just need to Read The Manual?), then “(sudo?) reboot”, which rebooted without activation. At one point, I was given three choices to boot: the normal, something I think was called recovery or rescue mode, and some third (I think these are from an app). I tried the second choice, and after nothing seemed to happen after about thirty seconds, I removed the battery (I suspect this was the Big Mistake, but maybe there should be a warning display for dolts).

I believe the phone worked normally for a while after that, but eventually (maybe after another reboot), it got stuck on the blinking five-dot stage, and that’s all the phone can do now: press the small on/off button on top, the white LED comes on, the bright Nokia logo shows, and then the five-dot runs back-and-forth, apparently forever (I’ve left in on for about an hour); pressing the on/off button again turns it off. For a while, briefly pressing the on/off button would pause the dots, but no longer. I don't think there is anything wrong with the batteries (except that I charge them externally).

Note that I can't connect to the phone by USB, since the USB receptacle slipped out some time ago. Am I screwed, until I can fix the USB? And once I have a USB connection, can I just copy in some corrupted files, or do I need to do a full re-flash? And if the latter, should I be able to copy out the flash drive's contents first (with dd, if nothing else)? I don't want to lose the user-contents. A sketch of possible, data-preserving steps to take would be appreciated.

I will have to learn all about flashing, but maybe that isn't necessary here.

Alternatively, is it fairly easy to transplant the flash drive into a new n900, and recover things that way?

That application which gave you the three choices on boot, is it Backup Menu? Because if it is, you are in luck, as you might be able to make your system bootable just by copying a backup image to microSD. I think RobbieThe1st (the author of Backup Menu) posted some backup images from a fresh system.

If you reboot with the keyboard slid open, do you get the Backup Menu prompt?

If you do, report back, but don't do anything yet (you might want to FSCK your partitions before doing anything more drastic).

BTW, the problem you are having points IMO to a problem with your /home/user partition. I might be wrong though.

And the "flash drive" is not transplantable I'm afraid. It's not on a socket, but soldered in the system board.

Instead of doing quite-hard repair of USB port itself, you could connect to testpads beneath battery - there is USB connections, too. Either solder to the pads (and de-solder later - easy todo, but be carefull to not rip testpads), solder with thin wires and leave it there/connect to new USB port, or create a re-usable under-battery connector, using some springs (hardest, but most reliable).

BTW, trying to replace busybox with bash for things including boot-time, in a device without USB functioning was a *extremely* bad idea. You could have avoided catastrophe by installing u-boot first (and then, boot from microSD into some rescueOS or whatsnot), but not, it's a little too late

/Estel

@malfunctioning, it's likely the Backup Menu; I think it isn't something original. As far as I know, I can't get the phone to do anything except what I described - is there some special way to reboot? I'll try with the keyboard open. Sorry for delay, the n900 was my only home internet connection. @Estel, I'm thinking that the USB port could be repaired by first using a conductive cement for the 'hidden' pins, then soldering the outer sides. I'll look at the related threads.

Yes, keyboard open should do it. You will need a microsd card with backup images. I think RobbieThe1st provided some. Take a look at the Backup Menu official thread, let me know if you have trouble finding something, and maybe I can help you.

@tfj,

If you also have "Recovery console" in your bootmenu. Try that, edit /etc/profile and fix whatever you added/replaced/removed there.

To edit you can use "nano".

@reinob - There's Recovery mode, but that isn't working ... I'll try re-editing /etc/profile when I regain control, but I wouldn't think that would cause such a problem - I was getting some common shell error messages (something similar to 'unexpected character'), though.

Aha - turning the phone on with the keyboard open displays "Loading BOOT MENU..." on the Nokia logo screen, then shows the three boot-choices - is this a standard n900 feature? (Incidentally, I haven't seen the large 'Backup Menu' menu, so it probably isn't installed).

Here are the three choices:

Maemo 5 (Internal Nand)
Recovery (Internal flash)
Power Off (only when not charging)

and, at the bottom of the page:

Press HOME/CTRL key for USB mass storage mode
Press HOME/SHIFT key for USB network mode

(What are these keys on the n900? And, is there any way to connect to this crippled phone wirelessly?)

When I select the first boot method, I get the endless Five-Dot back-and-forth.

When I try the second method, "Booting from nand (mtdblock4 jffs2)..." and "Starting recovery.sh..." is displayed for about one to twenty seconds on a bright screen, then the screen goes dark, and at some point the phone shuts off (only the on button works). I recall having a short (± 20-line) script named 'recovery.sh' in the root directory.
Note: this is similar to what happened originally - after the phone went dark for a while, I paniced and yanked the battery. If, however, the phone had shut off, then removing the battery shouldn't have harmed anything (I'm guessing the phone hadn't shut off, since that would seem a pointless mode).

Are the last two instructions of any help?
Are there more special booting methods?