diff --git a/src/frontend/mame/ui/info.cpp b/src/frontend/mame/ui/info.cpp
index 93583ed85df..18a2039e5d4 100644
--- a/src/frontend/mame/ui/info.cpp
+++ b/src/frontend/mame/ui/info.cpp
@@ -54,24 +54,6 @@ machine_info::machine_info(running_machine &machine)
 }
 
 
-//-------------------------------------------------
-//  find_dipname - look up DIP switch by name
-//-------------------------------------------------
-
-ioport_field *machine_info::find_dipname(const char *name) const
-{
-	if (!m_has_dips)
-		return nullptr;
-
-	for (auto &port : m_machine.ioport().ports())
-		for (ioport_field &field : port.second->fields())
-			if (field.type() == IPT_DIPSWITCH && strcmp(field.name(), name) == 0)
-				return &field;
-
-	return nullptr;
-}
-
-
 /***************************************************************************
     TEXT GENERATORS
 ***************************************************************************/
diff --git a/src/frontend/mame/ui/info.h b/src/frontend/mame/ui/info.h
index b31726ba27f..b718c2acf64 100644
--- a/src/frontend/mame/ui/info.h
+++ b/src/frontend/mame/ui/info.h
@@ -31,8 +31,6 @@ public:
 	bool has_keyboard() const { return m_has_keyboard; }
 	bool has_test_switch() const { return m_has_test_switch; }
 
-	ioport_field *find_dipname(const char *name) const;
-
 	// text generators
 	std::string warnings_string();
 	std::string game_info_string();
diff --git a/src/frontend/mame/ui/ui.cpp b/src/frontend/mame/ui/ui.cpp
index a21b1e82cee..bda9bdcf3be 100644
--- a/src/frontend/mame/ui/ui.cpp
+++ b/src/frontend/mame/ui/ui.cpp
@@ -257,11 +257,14 @@ void mame_ui_manager::initialize(running_machine &machine)
 		slider_current = nullptr;
 	}
 
-	if (!m_machine_info->has_test_switch())
+	// if no test switch found, assign its input sequence to a service mode DIP
+	if (!m_machine_info->has_test_switch() && m_machine_info->has_dips())
 	{
-		ioport_field *service_mode_sw = m_machine_info->find_dipname(ioport_configurer::string_from_token(DEF_STR(Service_Mode)));
-		if (service_mode_sw != nullptr)
-			service_mode_sw->set_defseq(machine.ioport().type_seq(IPT_SERVICE));
+		const char *const service_mode_dipname = ioport_configurer::string_from_token(DEF_STR(Service_Mode));
+		for (auto &port : machine.ioport().ports())
+			for (ioport_field &field : port.second->fields())
+				if (field.type() == IPT_DIPSWITCH && strcmp(field.name(), service_mode_dipname) == 0)
+					field.set_defseq(machine.ioport().type_seq(IPT_SERVICE));
 	}
 }