mainboard dead or io dead?

dear sirs im check my air because is dead!

the magsafe led is off, i check with a voltimeter as you can see in the pictures below, and in the main board conector has 14,8 v.

is the io board broken or there is any component in the main board that can i check to determine the fault?

i clean the main board with 98% alcohol and remount all the components.

Many thanks in advance.