My lovely N900 is out of service and I miss it (maemo.org > Talk > OS / Platform > Maemo 5 / Fremantle > Can't re-flash N900 because it wont turn off!)! The problem now has escalated, I think the counter may have reached 51! Now when I put a fresh battery in and plug in the USB cable I get a solid yellow LED but nothing else. Unfortunately mine was bought OS without warranty so sending it back to Nokia for replacement is a no go. I think I have read all the threads that include "won't boot" in the subject line and there are many! There seems no solution for me, no-matter what I try I simply can't get my N900 to boot. When a unit in this condition is presented to Nokia Service Centre do they just bin it? Or is there a fix? Any clues, tips, tricks?
Did anyone with this problem have their phone returned repaired from nokia or were they all replaced? Sorry....am I just grasping at straws?

Nothing is phenomenon here.
This is old. Reflash it, then it will be back to normal.

Yes...but how? It doesnt turn on! I get one yellow LED and no more.

It happened to me twice, just reflash the whole firmware and it should be working again

It could be the battery totally drained off - just wait at least half an hour before trying to execute anything letting BME do his job.
My suggestion is to leave the N900 under charge at least half a day, then disconnect the charger, wait half an hour, riconnect the charger and see if the yellow led starts blinking. Don't turn on your device!
Then follow http://wiki.maemo.org/Updating_the_firmware#N900

Note that the u key shall be pressed while inserting the USB cable and with device turned off, so:
- start flasher utility on your PC
- open the N900 keyboard
- press and hold u key
- while keeping u pressed, connect USB cable

HTH