Question Notebook cannot boot / start up

[it4u]

Acer Aspire 3004 WLCi, the battery can be charged (when plug in AC Power and switched on AC mains, the battery's LED changes from orange (ie low charge) to yellow (ie fully charged).

However, whether by battery alone or with AC Power, notebook cannot start up (ie cannot boot up).

Also, when AC Power is switched on, the AC Power LED does not light up

Please suggest / advise. Thank you

 

[it4u]

Additional info: the power adapter / cord has been tested and is in good working condition.
Both RAM and HDD has been tested on other notebooks, and both are in good working condition