change values in line of purchase if change product o not product

purchase.py

@@ -71,11 +71,22 @@ class Line(metaclass=PoolMeta):
     serial_equipment = fields.Char("Serial", size=None, required=True)
     refurbish = fields.Boolean("Refurbish")
     product_equipment = fields.Boolean("Product Equipment")
-
     
+    @classmethod
+    def default_address_equipment(cls):
+        pool = Pool()
+        Company = pool.get('company.company')
+        company = Transaction().context.get('company')
+        if company:
+            company = Company(company)
+            return company.party.addresses[0].id
+
     def on_change_product(self):
         if not self.product:
             self.product_equipment = False
+            self.address_equipment = None
+            self.serial_equipment = None
+            self.refurbish = None
             return
 
         party = None
@@ -104,14 +115,7 @@ class Line(metaclass=PoolMeta):
         self.amount = self.on_change_with_amount()
         if self.product.equipment:
             self.product_equipment = True
-
-    def default_address_equipment():
-        pool = Pool()
-        Company = pool.get('company.company')
-        company = Transaction().context.get('company')
-        if company:
-            company = Company(company)
-            return company.party.addresses[0].id
+            self.address_equipment = self.default_address_equipment()
         
     @classmethod
     def view_attributes(cls):