Originally Posted by Silvarum

There is page on wiki for reflashing. I think, your device just doesn't have kernel to boot with. So as wiki says:
1. Download flasher.
2. Download firmware image. You may need to enter your IMEI number.
3. Make sure, that battery is fully charged.
4. Hold the u key on the device keyboard and connect the USB cable at the same time. If necessary, hold the u key until Windows (i assume you using Windows) has successfully installed the driver. You should see USB icon on your N900, meaning it's in flashing mode.
5. Now, if your device just doesn't have kernel, then this command should work:

Code:

flasher-3.5 -f --flash-only=kernel -R -F <firmware-image>

If it doesn't work, then flash entire rootfs partition:

Code:

flasher-3.5 -f -R -F <firmware-image>