Machine construction.

code/ATMOSPHERICS/atmospherics.dm

@@ -217,7 +217,7 @@ Pipelines + Other Objects -> Pipe network
 
 	qdel(src)
 
-/obj/machinery/atmospherics/construction(D, P, C)
+/obj/machinery/atmospherics/on_construction(D, P, C)
 	if(C)
 		color = C
 	dir = D

code/game/machinery/Freezer.dm

@@ -44,7 +44,7 @@
 	min_temperature = max(0,T0C - (170 + (T*15)))
 	current_heat_capacity = 1000 * ((H - 1) ** 2)
 
-/obj/machinery/atmospherics/unary/cold_sink/freezer/construction()
+/obj/machinery/atmospherics/unary/cold_sink/freezer/on_construction()
 	..(dir,dir)
 
 /obj/machinery/atmospherics/unary/cold_sink/freezer/attackby(obj/item/I, mob/user, params)
@@ -193,7 +193,7 @@
 	component_parts += new /obj/item/stack/cable_coil(src, 1)
 	RefreshParts()
 
-/obj/machinery/atmospherics/unary/heat_reservoir/heater/construction()
+/obj/machinery/atmospherics/unary/heat_reservoir/heater/on_construction()
 	..(dir,dir)
 
 /obj/machinery/atmospherics/unary/heat_reservoir/heater/RefreshParts()

code/game/machinery/computer/computer.dm

@@ -19,6 +19,12 @@
 	overlay_layer = layer
 	..()
 
+/obj/machinery/computer/Destroy()
+	if(circuit)
+		qdel(circuit)
+		circuit = null
+	return ..()
+
 /obj/machinery/computer/initialize()
 	..()
 	power_change()

code/game/machinery/cryo.dm

@@ -52,7 +52,7 @@
 	component_parts += new /obj/item/stack/cable_coil(null, 1)
 	RefreshParts()
 
-/obj/machinery/atmospherics/unary/cryo_cell/construction()
+/obj/machinery/atmospherics/unary/cryo_cell/on_construction()
 	..(dir,dir)
 
 /obj/machinery/atmospherics/unary/cryo_cell/RefreshParts()

code/game/machinery/machinery.dm

@@ -396,15 +396,18 @@ Class Procs:
 /obj/machinery/proc/default_deconstruction_crowbar(var/obj/item/weapon/crowbar/C, var/ignore_panel = 0)
 	if(istype(C) && (panel_open || ignore_panel))
 		playsound(loc, C.usesound, 50, 1)
-		spawn_frame()
-		for(var/obj/item/I in component_parts)
-			if(I.reliability != 100 && crit_fail)
-				I.crit_fail = 1
-			I.forceMove(loc)
-		qdel(src)
+		deconstruct()
 		return 1
 	return 0
 
+/obj/machinery/proc/deconstruct()
+	on_deconstruction()
+	spawn_frame()
+	for(var/obj/item/I in component_parts)
+		if(I.reliability != 100 && crit_fail)
+			I.crit_fail = 1
+		I.forceMove(loc)
+	qdel(src)
 
 /obj/machinery/proc/spawn_frame()
 	var/obj/machinery/constructable_frame/machine_frame/M = new /obj/machinery/constructable_frame/machine_frame(loc)
@@ -573,7 +576,10 @@ Class Procs:
 	return 0
 
 //called on machinery construction (i.e from frame to machinery) but not on initialization
-/obj/machinery/proc/construction()
+/obj/machinery/proc/on_construction()
+	return
+
+/obj/machinery/proc/on_deconstruction()
 	return
 
 /obj/machinery/proc/can_be_overridden()