Heat Pumps and Electric Heating - Outside unit took a dump

My outside unit won't come on when in cool or heat. I can engage the points on the coil manually (with a stick) and the fan/motor will come on. After about a minute or so the compressor will kick-in and circulate the freon but the cooper tube gets red hot regardless of whether the thermostat is in cool or heat. I should also mention that one of the relays on the defrost control board is clicking the whole time but only when tsat is in cool..when tsat is in heat there is no clicking of relay. I metered the coil and getting 24v and all the terminals on the defrost board are 24V except the terminal for the defrost control sensor (3V).

Inside unit is working fine.

It's a split system with emergency/aux heat. Brand name is International Comfort Products.

Question/s:

Could a bad defrost control board be causing the contact on coli not to engage....also causing what I bebieve to be a "stuck" reversing valve?..or is the defrost sensor itself the culprit?

Thanks for any suggestions or solutions

Yes Id say go for the defrost board. What you hear is the 4 way valve. That has to pull in for the unit to go into cool and defrost , it dont for heat.