I bought a second-handed Nokia N900 and planning to upgrade it to Maemo 5 CSSU edition, of course it needed a restart but after it restarted the device asked me to enter the lock code.

I have read through the forum but the unlocking method only involves the situation where you can still access your N900. My case is i can't do anything with it now as it requires me to enter lock code first!

Is there any way to unlock it without sending to Nokia Service Centre? Because im cashless right now..

Pic related:

Have you tried contacting the person you bought it from to find out what the lock code is?

You can also try 12345, I THINK that's the default lock code...