diff --git a/qml/Desktop.qml b/qml/Desktop.qml
index 457f783..3f15519 100644
--- a/qml/Desktop.qml
+++ b/qml/Desktop.qml
@@ -24,7 +24,7 @@ Item {
 
 	Tuner {
 		id: tuner
-		running: true
+		running: false
 	}
 
 	DesktopTheme {
diff --git a/qml/TunerScreen.qml b/qml/TunerScreen.qml
index 4268205..d1f553a 100644
--- a/qml/TunerScreen.qml
+++ b/qml/TunerScreen.qml
@@ -149,4 +149,11 @@ Item {
 			index: tuner.octave
 		}
 	}
+
+	MouseArea {
+		anchors.fill: parent
+		onClicked: {
+			tuner.running = tuner.running ^ true
+		}
+	}
 }
diff --git a/src/PitchDetection.cpp b/src/PitchDetection.cpp
index ce1e5c8..3d3d643 100644
--- a/src/PitchDetection.cpp
+++ b/src/PitchDetection.cpp
@@ -222,6 +222,10 @@ void PitchDetection::analyse_file(const char *filename)
 	cout << "analyse file " << filename << endl;
 	ifstream fin;
 	fin.open(filename);
+	if (!fin.is_open()) {
+		cerr << "file not opened" << endl;
+		return;
+	}
 
 	const int nb_frame = 1024;
 	PitchDetection *pitch = new PitchDetection();
diff --git a/src/Tuner.cpp b/src/Tuner.cpp
index 64e05aa..7c29bdf 100644
--- a/src/Tuner.cpp
+++ b/src/Tuner.cpp
@@ -42,12 +42,6 @@ Tuner::Tuner()
 	connect(&workerThread, &QThread::finished, worker, &QObject::deleteLater);
 	connect(&workerThread, &QThread::started, worker, &TunerWorker::Entry);
 
-	connect(this, &Tuner::quit, worker, &TunerWorker::Quit, Qt::DirectConnection);
-	connect(this, &Tuner::start, worker, &TunerWorker::Start);
-	connect(this, &Tuner::stop, worker, &TunerWorker::Stop);
-	connect(this, &Tuner::setTemperamentIndex, worker, &TunerWorker::SetTemperament);
-	connect(this, &Tuner::setLa, worker, &TunerWorker::SetLa);
-
 	connect(worker, &TunerWorker::resultUpdated, this, &Tuner::ResultUpdated);
 	connect(worker, &TunerWorker::temperamentListUpdated, this, &Tuner::TemperamentListUpdated);
 
@@ -56,9 +50,9 @@ Tuner::Tuner()
 
 Tuner::~Tuner()
 {
-	quit();
-//	workerThread.quit();
-	workerThread.wait(10);
+	worker->Quit();
+	workerThread.quit();
+	workerThread.wait(100);
 }
 
 bool Tuner::GetRunning()
@@ -71,8 +65,8 @@ void Tuner::SetRunning(bool r)
 	if (running == r) return;
 
 	running = r;
-	if (r) emit start();
-	else emit stop();
+	if (r) worker->Start();
+	else worker->Stop();
 
 	emit runningChanged();
 }
@@ -105,7 +99,7 @@ bool Tuner::GetFound()
 void Tuner::SetLa(double la)
 {
 	this->la = la;
-	emit setLa(la);
+	worker->SetLa(la);
 	emit laChanged();
 }
 
@@ -122,7 +116,7 @@ unsigned int Tuner::GetTemperamentIndex()
 void Tuner::SetTemperamentIndex(int idx)
 {
 	temperament_idx = idx;
-	emit setTemperamentIndex(idx);
+	worker->SetTemperamentIndex(idx);
 	emit temperamentChanged();
 }
 
diff --git a/src/Tuner.hpp b/src/Tuner.hpp
index 1d40593..7960a86 100644
--- a/src/Tuner.hpp
+++ b/src/Tuner.hpp
@@ -75,13 +75,6 @@ class Tuner : public QObject {
 	void resultChanged();
 	void temperamentChanged();
 	void temperamentListChanged();
-
-	// signals to worker
-	void quit();
-	void start();
-	void stop();
-	void setTemperamentIndex(int idx);
-	void setLa(double la_freq);
 };
 
 #endif
diff --git a/src/TunerWorker.cpp b/src/TunerWorker.cpp
index 1e1b3ab..ce3cb39 100644
--- a/src/TunerWorker.cpp
+++ b/src/TunerWorker.cpp
@@ -28,7 +28,7 @@ using namespace std;
 
 static void blank_prevent(bool prevent)
 {
-	cerr << __func__ << endl;
+	cerr << __func__ << " " << prevent << endl;
 	QDBusConnection system = QDBusConnection::connectToBus(QDBusConnection::SystemBus, "system");
 	QDBusInterface interface("com.nokia.mce", "/com/nokia/mce/request", "com.nokia.mce.request", system);
 
@@ -63,6 +63,7 @@ void TunerWorker::Start()
 
 void TunerWorker::Stop()
 {
+	cerr << __func__ << endl;
 	mutex.lock();
 	running = false;
 	mutex.unlock();
@@ -84,7 +85,7 @@ void TunerWorker::SetLa(double la)
 	mutex.unlock();
 }
 
-void TunerWorker::SetTemperament(int idx)
+void TunerWorker::SetTemperamentIndex(int idx)
 {
 	mutex.lock();
 	temperament_to_update = idx;
@@ -94,6 +95,7 @@ void TunerWorker::SetTemperament(int idx)
 void TunerWorker::Entry()
 {
 	cerr << __func__ << endl;
+
 	pitchDetection = new PitchDetection();
 	emit temperamentListUpdated(pitchDetection->GetTemperamentList());
 
@@ -124,6 +126,8 @@ void TunerWorker::Entry()
 
 		std::cout << __func__ << " do job" << std::endl;
 	}
+
+	cerr << __func__ << " quit" << endl;
 /*
 	// prevent screen blanking
 	if (nb_sample_running >= nbSamplePreventRunning && running) {
diff --git a/src/TunerWorker.hpp b/src/TunerWorker.hpp
index b6acfc1..3cfe150 100644
--- a/src/TunerWorker.hpp
+++ b/src/TunerWorker.hpp
@@ -55,7 +55,7 @@ class TunerWorker : public QObject {
 	public slots:
 	void Start();
 	void Stop();
-	void SetTemperament(int idx);
+	void SetTemperamentIndex(int idx);
 	void SetLa(double la);
 	void Entry();
 	void Quit();