Hello everyone,

I know there's a lot of threads about N900s not booting/starting problem but I've not yet seen one like mine (I did search the forum thoroughly but sorry if I missed a similar thread still).
In short: phone works normally most of the time. When I reboot it or battery dies, it will not start up on first few tries (number of retries seems to vary randomly). Removing the battery doesn't seem to corelate to the rate of boot up success.
Unsuccessful attempts end up in shutdown before getting to the 5 loading dots. Loading dots mean success.
Dead battery is not the problem - I have several spares and stuff happens with any of them.
Charging happens normally when turned off.

CAUSE: kernel-power-settings loads custom kernel settings upon boot, which somehow conflict with kernel-power (I have power50). To reproduce it suffices to overclock (with qcpu) and save the settings.
SOLUTION: uninstall kernel-power-settings (together with other software that depends on it). Be aware that reflashing the kernel might be necessary in some scenarios:

Code:

flasher-3.5.exe -F <combined image name> --flash-only=kernel -f -R

After which installing kernel-power-flasher will bring back the POWER

Usual scenario:
shutting down phone (for whatever reason)
turning on by power button
white LED + vibration + Nokia logo
after several seconds screen goes dark and phone shuts down with fading amber LED
next try after Nokia logo phone again turns off, this time with fading white LED
next try results in one of the above
next try occasionaly results in normal boot up, but usually doesn't
removing/replacing battery
next try usually fails again
next try usually succeeds

On average there are about 5-6 unsuccessful attempts before a good boot.

Soo... main question is: has this problem been encountered before and is there a known cause? (I can live with it and don't want to reflash because it's working great in all other aspects.)
Secondary question: what does a fading out amber LED mean (while phone is shutting down, obviously)?

Background device info (probably useless reading):
Had this same problem with my previous n900 that I don't use anymore because of broken off USB. Have backed it up with backupmenu to SD and restored the OS in it's entirety on a "new" phone (actually a used phone bought off ebay).
New phone was working normally before restoring from old phone, so I am pretty certain it's not a hardware problem.
Before this transplantation last reflash was more than a year ago, so I guess there might be something wrong with the software (did a lot of experimenting during that time including NITdroid, rd mode and build-essential).
Problem started manifesting on old phone during the time the USB came off.

How long are you leaving your phone off before reattempting to reboot?

The n900 does need to be left powered off for at least 8 seconds before attempting to reboot.

reflash kernel only, it won't affect apps you have installed.

flasher-3.5.exe -F RX-51_2009SE_21.2011.38-1_
PR_COMBINED_MR0_ARM.bin --flash-only=kernel -f -R

Thanks for your quick reply but unfortunately it's not that. I know maemo is still shutting down even after the white LED faded out.
I wait as long as needed until the phone starts responding to power button again.


That might help. Will try tonight and come back with the results. Thank you.

Sounds like you need a clean reflash as your backup is buggy in some way, it is not that a big deal if you use osso-backup and export your contacts. I would flash both emmc and rootfs.

EDIT: I doubt it is the kernel only but I'd try that first anyway.

same prob here... and... usb broken so I can't reflash...

Can you successfuly boot at all..after 2,3...10 tries? If yes, try to install power kernel, I think it might help.

Disassambe phone and take your mboard and jack to any mobile service-centre. It cost me 3€ to solder it back.

dzano thanks... but I'm not able di dissasemble it...

this might not relevant to the fault you are facing but did you try on any other battery?

Try pulling the battery for an hour, and then see if it'll boot (after putting the battery back in). This has consistently worked for me.

Though this still doesn't address the main issue, which I'm not sure what it is. I'll need to reflash it at some point, it seems.