code 23 and 24 are related to the contactor coil circuits on the fwd and rev circuits.
since you have replaced all the contactors i guess we can rule out the fwd/rev coils being the problem.
I would double check the wiring between the fwd/rev coils and the pb4 and 5 connections on the card. Also i've found when there are connection issues between the card and the components on the control panel it sometimes can be found in the connectors themselves.
you can take a small pair of needlenose pliers and remove the plugs on the control card, take the needlenose pliers and go into the socket on the card and put a slight twist on the pins to improve connection. DO NOT twist them alot, but just enough to help make a better connection.
Also you can remove the 2 center filter rec's on the spiderblock and check the choke coil wire connection behind this, there will be a lone screw where 2 white wires connect in the choke coil circuit, make sure this screw is tight and holding the wire down securely.