[Edit: this has been solved and is no longer a problem.]

There seems to be a fatal flaw in the N900! Please help me figure out how I can avoid having to return my N900.

I keep having an error on boot-up where, after the Nokia logo comes and goes, the flashing dot sequence continues indefinitely, for hours; boot-up is never completed. The N900 becomes unusable. While in this state, if I try:
- tapping on/off button: flashing dots pause for a moment, then continue flashing forever as before
- holding on/off button: device switches off; but when I switch it back on, after the Nokia logo we're back to the forever flashing dots
- taking out the battery and replacing: same as holding on/off button

There is no problem with "lock screen and keys": screen turns off, N900 looks just like it's off, etc. except it will still accept phone calls, etc., and I can "turn it back on" (I guess the correct term is "unlock screen and keys") and it works. But after I've used a new N900 for a few days, if I actually turn it off (hold on/off button until device powers down), then I get this problem on boot-up.

I tried to avoid turning it off/on, but there were a few times when I had to reboot:
- sometimes installing certain applications (like BlessN900) requires a reboot
- the system becomes unstable: it responds more and more slowly (at times taking 30 seconds to respond to a tap), or the Settings program will spit out some error message and refuse to edit profiles
- the N900 is designed that, to insert/remove a SIM card, I have to take out the battery, forcing a reboot. (With the N900 so unreliable, I need to insert/remove the SIM to make calls with an old cell phone.)

This is what I've tried:
- returned the N900 to the store for a refund, got another N900 (both were brand new). This boot-up error occurred with both devices.
- updating the firmware to Maemo 5 PR 1.2, via Internet. The error still occurred.
- flashing the firmware

When the N900 goes into this "forever dots" state, there is only one thing I've found which can make it usable again: I have to flash the firmware and the "eMMC" image (I think this is the 25GB memory). (It's not enough just to flash the firmware.) The N900 does respond to putting it into "USB flashing mode" (where you connect via USB to the computer while pressing the 'u' key), and flashing firmware+eMMC results in a blank device, for which the data has to be restored. With my first N900 I did not know how to do this, and had to return it to the store. With my second N900, I have had to flash to overcome this error about 4 times (in the past month).

Unfortunately, this means that when the N900 goes "forever dots" on me, I can't do anything until I can hook it up to my computer with a flasher program, firmware image and eMMC image. It's a bit scary to think that, if my car breaks down on a deserted highway (I commute 90 minutes to work), I might not be able to call for help because my N900 has decided to go into infinite booting. It would defeat the purpose of having a lightweight handheld computer like the N900 if I always have to lug around my laptop so I can flash firmware+eMMC and then restore my contacts list so I can call for help. Thus far I've taken to carrying my old phone around, a Treo 650 --which, by the way, has a hardware reset button that breaks out of any infinite loops. I hope Nokia puts one into their phones in the future.

So, unless I can resolve this problem, I find that I cannot rely on the N900 for a phone. In that case I might as well buy a much cheaper Internet tablet without phone capabilities, or just stick with my aging Treo. The deadline for returning my N900 to the store is coming up in 2 days, and I hope some of the readers here can come up with some insight before I am forced to refund what would otherwise be a very powerful and versatile device because of a bug in the operating system.

Some notes:
- I did not install any software other than from repositories already enabled by default (that is, no extras-devel or extras-testing).
- I tried to isolate which software might be causing the error, by installing/not installing various combinations of software. In particular, I heard that Catorize would trigger a bug when the applications menu was not a flat structure, but the error still occurred without Catorize present.
- this does not seem to be the same error mentioned on other threads where, after the N900 is finished booting up, it reboots. Apparently that error was resolved with the newest version of the firmware.

You must be very unlucky if this happened to you twice. After flashing are you reinstalling your previous software? Maybe one of them is causing this. And try booting without a microsd. Try flashing with different versions of PR 1.2 (global, UK etc)

Are you sure you haven't enabled extras testing or devel because if you have tried BlessN900 you have them enabled. If you have enabled either of them maybe something from there is causing your broblems.

Get another one while you can, if you encounter the same problems the problem lies between the chair and the N900!

sounds like you have something installed that causes this, if not then have you transferred any media to it that may contain a virus although its linux rather than windows or mac a virus targeted at them can cause random problems for you so either scan all your media that you transferred and all the emails or remove all downloads that aren't from the stock catalogs.
if it is down to a virus you got then you'll have to re flash, make sure you use upto date os and emmc

Do you use a SIM?

Some of the other members of the #maemo IRC channel also said that it was my fault that two of the N900's went into an infinite loop on boot-up, but we couldn't figure out exactly what I was doing to cause this. If you could help figure this out, it would show that you're not just posting unhelpful comments here.

These are the possibilities I thought of:
- Is it because I'm installing weird software? Three times out of four, I did not enable any new repositories, but I guess it could be that software that has gone through extras-devel, promoted to extras-testing, and has had enough votes to go to just plain extras, could still have some weird bug. (One time the error triggered because I enabled extras-devel to install BlessN900, but that time there had been no system slowdown or weird error messages.)
- Is it because of a bad SIM card? Forum members said that this was next to impossible (to have this error, not to have a bad SIM card)
- Is it because of a bad microSD card? Forum members said that this was next to impossible (to have this error, not to have a bad microSD card)
- Is it because I created a symlink from ~/ to ~/MyDocs/.documents? "~/" is on a Linux filesystem (ext3 or ext2 or whatever) while ~/MyDocs/.documents is on vfat, so maybe that blew it up. But if I recall correctly, the error happened even without the symlink.

Any advice would be appreciated.

@MiK546: I did not enable extras-testing/extras-devel out of fear, but the error happened nonetheless.

After a while I got sick and tired of not installing anything out of fear, and decided to do it. As far as I can tell, it doesn't make a difference whether or not I enable extras-devel/testing. (Btw, I immediately disabled extras-devel/testing to make sure nothing stable would get accidentally updated to a newer, buggier version.) I think BlessN900 is extras-testing, not extras-devel. I also installed Midnight Commander, which is essential for browsing and retrieving files over ssh; MohammedAG says it's rock-solid stable, and I believe him.

@Matthew Maude: I, too, suspect something installed but can't tell what it is. All the files I transferred to the device were backups from the device. I don't have any downloads that "aren't from the stock catalogs", as I had mentioned. It seems rather unlikely that a virus would have gotten onto my Kubuntu system and then transferred onto the N900 (which doesn't even use a x86 processor), but I had already followed your suggestion of "you'll have to re flash, make sure you use upto date os and emmc" several times, as I noted in my previous posting.

@YoDude: Yes, I do use a SIM. Do you think it could be because of a bad SIM card? I have been using the same SIM in my old phone for about six years now; I'm not sure I want to change it because I would have to change my phone number (among other hassles that outweigh the disadvantage of just not using a N900).

@pantera1989: Thanks for the suggestions. This is probably the most helpful reply so far. On reflection, it is conceivable that it's the MicroSD, since:
- if the bootup sequence involved checking something about the MicroSD, an error might launch it into an infinite loop
- if this problem occurs, it's easy to remove the microSD card; unlike the SIM card, I don't have to remove the battery to remove the microSD card
- I'll try flashing different versions of PR 1.2, although chances of success are slim. When I tried to flash just the firmware, the problem remained; I had to flash the eMMC also in order to get a working system again, so I think the problem is not in the firmware. But it's worth trying.

I guess my point is that I don't think it's just luck. It looks like there's a problem inherent in the N900. Other forum members have told me that they have been using the N900 for a long time with no problems, but that doesn't really help me. Even if I'm able to use the N900 from now on with no problems, until I can figure out what caused the problem I cannot rely on it: my phone might go wonky on me at any time, and in this day and age of relying on cell phones, this is not an acceptable situation.

You can get a new SIM card from you network operator and your number won't change.

Try taking the SIM card out (and memory card) and booting the tablet up, you can use it fully (minus making phone calls) without it.

@KWTM, there is a guy on nokia's maemo forum called cpitchford who has a debug program you can run then email him the results i don't have a link but if you ask on there he might be able to help and hes a linux genius so it could be your best option

What JD4200 said:

Run it without the SIM or the MMC.

The dot state is when the device is loading drivers and whatnot, seeing what resources are available, and preparing for how it expects to be used.

I do not know if in this state it is querring the phone network and waiting for an answer that might not come or it if it is reading the MMC and gets hung up there...

Try it sans SIM and MMC. If you're now good to go, add the SIM, [if/then] yadda yadda yadda...

EDIT: I just saw this:

Definitely loose the symlink too! Add that last in your [if/then] trials.