So I've uploaded the blinking led sketch on my arduino uno (r2) and make sure it worked.
The i've take off the atmega and put it on the breadboard following the instructions in http://www.arduino.cc/en/Main/Standalone.
But the led does not blink.
I've tried many times but still nothing.
What do I miss ?
Is it possible to do with an arduino uno or am I wasting my time ?
It's possible your switch is shorting reset to Gnd. Try removing the Gnd connection to the switch.
If that works, move your GND connection to the other side of the center-divider.
It's also possible your LED is backwards. Try flipping it around. You want the short leg (that has flat spot on the lip of the LED) going to the resistor.
The possible causes are:
Open wire/s
5 Volts not present or too low - Bad regulator
328 pin bent under.
Reset switch not working.
Open resistor.
LED does not work.
Bad breadboard
You should be able to determine what problem it is using a volt meter.