|This may be tooo simple to even consider but it has worked before, unless your AC Power LED is NOT lit with the adapter Plugged in to the AC.|
Check the Power Switch lock. It may be only a little tab above or below the switch. It's relatively easy to engage the lock without knowing it.
Still, though, you should see the AC charge indicator LCD on the front panel.
Pull the battery and try with AC adapter only. Clean the Battery contacts on LT and Battery.
There is nothing to learn from someone who already agrees with you.