XploitMachine wrote:1. Turn OFF
2. Take out the memory card
3. Turn ON
4. Its going to homescreen rite?
why does everyone assume a dam memory card is at fault when these things happen? with the N97 and even N97 mini, there is enough onboard storage to make removable media rather obsolete.
to the O.P. - i also have this issue, FREQUENTLY, with my N97-NAM (original, not mini, same issue). I used to hard reset it when this happened, but i find that a hard reset only fixes it for a short while. online i tend to see basically three perspectives from potentially helpful people:
1. remove the memory card (personally, i assume you don't even have one. i don't)
2. uninstall some application you recently installed (assuming you could... for me, the issue never seems to originate soon after installing any apps, but rather the phone freaks out during normal use causing me to restart it and find that it wont boot up. so i call this advice useless as well).
3. do a hard reset (for me, this sucks. i dont run windows so i dont have a usable backup/restore option. on top of that i find the problem persists anyway. doing a restore, if you have the option, is likely to restore the soon-to-cause-a-complete-failure system state anyways).
Some time ago i read a few posts about the white screen of death (wsod, that's the name people have given to your issue) and how it appeared to relate to the USB port and the way the phone boots up in order to a) be a phone; b) charge; c) be a mass storage device; etc.
the theory posited was that the firmware would fail to boot because some state flags were not being reset, but that you could trick the phone into booting by following a simple process like this:
1. turn off the phone (remove battery and reinsert, if needed to turn it off)
2. plug in usb charger, the screen will turn on (continue to next step before Nokia logo appears)
3. unplug usb charger, the screen will turn off (continue to next step before the screen actually turns off)
4. just before the screen turns off, press the power button to start the phone normally
at the time i thought the idea made sense - you're sort of forcing a race condition to get the phone to escape an otherwise failed state. i tried it, it didnt work for me, so i ignored it after that.
recently i again read one of these posts, as i was frustrated with yet another wsod. this time it worked. the above 4 steps are my version of the process, the one that works for me. in other forums the steps are described slightly differently, but the essence is that you want to get the phone to be in the process of booting in one mode and interrupt it with a request to boot in the normal phone mode.
others have reported that their phones will boot up and the issue does not recur (at least not immediately). sadly i cannot verify this - for me the phone will not boot normally again until i do a hard reset, and even then if i don't format the mass storage it will revert to this failure state again often within 1 day of my hard reset.
good luck,
-bit
Thanks "bitflung"
My N97 locked up, on the "wsod" , after the battery came off, i have the phone on a magnet, an have metalstrips, glued to the batery, works great, as long as one holds the phone on the back, when i grab it.
However, not today, so it locked = GRRRR "WSOD"
And, no I dont have a memorcard, so that was`nt it.
But, the in and out, with the usb charger worked
so Thanks a million 
you're welcome!
glad to see that this post is still helpful for ppl. i wonder if there is a way to make it stand out more or become more visible to users that might suffer this symptom.
by the way, i sold my N97 and now have an N900. there is just no comparison, the N900 is a fantastic device. solidly built, fast, clean, very impressive. since it doesn't run Symbian i have of course lost all the apps i've bought over the years (it's amazing to look back and realize that i had over $200 worth of symbian apps in my collection). but i tell you, it's worth it.
i've had the n900 since mid february and i haven't had a single reason to dislike it. the phone has not frozen (never required pulling the battery), and of course i haven't had to do a single hard reset (not even sure how to do one on this device, never needed to look it up). everything is fast and responsive, mail works great and is full html with proper kinetic scrolling... etc etc etc. basically the n900 is everything i had hoped for in the n97, and goes beyond those hopes in some very meaningful places (i never thought i'd be installing google's chromium web browser, but it runs pretty well - and full flash 9.4 support with 10.1 coming this summer too!)
-bit
