Ok I 've just done that, the router didn’t do the 3 or 5 times blinking but seemed to boot normally (and yes I was pressing firmly on the rest button). But now the I can’t establish an Ethernet connection with it and its SSID doesn’t appear anymore.
As I’ve no access to the LAN I can’t change my IP to 192.168.1.2
I think this model is defective, I’ve just received it from Amazon, still sealed and didn’t have the chance to mess with its configuration.