ok. 1st : i have electricity at home, loki_ , forasmuch i can reply now. 2nd: i have completly disassembled my laptop. i have consulted the service manual, the schematic, etc.... and i have learned that some laptops have an internal protection such a small fuse, resistor, something..., others don't have. Actually the question is: has my HP such a protection?. The ac adapter was changed with a "compatible" one. From now on, no power light, no sound. It is clearly something is broken, and yes i have tested the connector conductivity on the mainboard with a digital multimeter and is ok. My only chance is to change this pseudo-protection zone, chip, component (however the jappanese have named it.) if it has, since the electrical shock was not so powerfull to pass it.