update_appearance

code/modules/power/power.dm

@@ -104,15 +104,23 @@
 /obj/machinery/proc/removeStaticPower(value, powerchannel)
 	addStaticPower(-value, powerchannel)
 
-/obj/machinery/proc/power_change()		// called whenever the power settings of the containing area change
-										// by default, check equipment channel & set flag
-										// can override if needed
-	if(powered(power_channel))
-		stat &= ~NOPOWER
-	else
+/obj/machinery/proc/power_change()
+	//SIGNAL_HANDLER
+	//SHOULD_CALL_PARENT(TRUE)
 
-		stat |= NOPOWER
-	return
+	if(stat & BROKEN)
+		return
+	if(powered(power_channel))
+		if(stat & NOPOWER)
+			SEND_SIGNAL(src, COMSIG_MACHINERY_POWER_RESTORED)
+			. = TRUE
+		set_machine_stat(stat & ~NOPOWER)
+	else
+		if(!(stat & NOPOWER))
+			SEND_SIGNAL(src, COMSIG_MACHINERY_POWER_LOST)
+			. = TRUE
+		set_machine_stat(stat | NOPOWER)
+	update_appearance()
 
 // connect the machine to a powernet if a node cable is present on the turf
 /obj/machinery/power/proc/connect_to_network()