İ cant open my laptop

Hello i have old DELL INSPIRON6400 laptop

And i cant open it

Right after i press powe putton it says this

The AC power adapter type cannot be determined.Your system will operateslower and the batery will not charge

((Please connect a Dell 65W AC adapter or higher for best system operation .To resolve this issue, try to restart the power adapter. Strike the F3 key (before the F1 or F2 key) if you do not want to see power warning messages again.

  Strike the F1 key to continue, F2 to run the    setup utility Press F5 to run onboard         diagnostics.))

İf i press F1 it gives me same screen

İn F2 menu there is nothing i can understand or do

When i press F5 it starts a kind of test and it gives me the error 0146