I would do basic check for all functionalities... When you turn on A/C,
touch the fatter freon line... is it icy cold? You may have to wait five
minutes with all windows closed... or if it is cold out there, leave it
open. If the line is cold, then you got enough freon... if not, you are low
or empty. Also look in the accumulator sight glass, you may have to put a
drop of water in there to clear up the sight glass... if it is bubbling, you
are low on freon... dry and oily is empty... clear is plenty of freon.
Then I would check the heater control valve... that big thing you have...
find which one of the hose come from water pump... clamp it shut... if heat
subsides, then yep, it is that logic board fried.