diff --git a/apps/hardware_test/vblank_test_controller.cpp b/apps/hardware_test/vblank_test_controller.cpp
index 61e4d2b3a..9736c921c 100644
--- a/apps/hardware_test/vblank_test_controller.cpp
+++ b/apps/hardware_test/vblank_test_controller.cpp
@@ -12,23 +12,14 @@ bool VBlankTestController::handleEvent(Ion::Events::Event event) {
       // Handled in WizardViewController
       return false;
     }
-    assert(strcmp(m_view.vBlankStateTextView()->text(), k_vBlankLaunchTest) == 0);
-    m_view.setColor(KDColorRed);
-    m_view.vBlankStateTextView()->setText(k_vBlankFailTest);
-    static_cast<AppsContainer *>(const_cast<Container *>(app()->container()))->redrawWindow();
-    /* We redraw the window with "VBLANK FAIL" before lauching the test. This
-     * test might end up in an infinite loop, in which case "VBLANK fail" keeps
-     * being displayed. If the test succeeds, the screen should change very
-     * quickly to "VBLANK OK". */
-    Shared::POSTAndHardwareTests::VBlankOK();
-    m_view.setColor(KDColorGreen);
-    m_view.vBlankStateTextView()->setText(k_vBlankOKText);
   }
   return true;
 }
 
 void VBlankTestController::viewWillAppear() {
-  m_view.vBlankStateTextView()->setText(k_vBlankLaunchTest);
+  bool testOK = Shared::POSTAndHardwareTests::VBlankOK();
+  m_view.setColor(testOK ? KDColorGreen : KDColorRed);
+  m_view.vBlankStateTextView()->setText(testOK ? k_vBlankOKText : k_vBlankFailTest);
 }
 
 VBlankTestController::ContentView::ContentView() :
diff --git a/apps/hardware_test/vblank_test_controller.h b/apps/hardware_test/vblank_test_controller.h
index b52fdc95b..951394586 100644
--- a/apps/hardware_test/vblank_test_controller.h
+++ b/apps/hardware_test/vblank_test_controller.h
@@ -32,7 +32,6 @@ private:
   };
   constexpr static const char * k_vBlankOKText = "VBLANK: OK";
   constexpr static const char * k_vBlankFailTest = "VBLANK: FAIL";
-  constexpr static const char * k_vBlankLaunchTest = "Launch VBLANK test";
   ContentView m_view;
 };
 
diff --git a/apps/on_boarding/power_on_self_test.cpp b/apps/on_boarding/power_on_self_test.cpp
index 3d3d4e22a..f5e614c86 100644
--- a/apps/on_boarding/power_on_self_test.cpp
+++ b/apps/on_boarding/power_on_self_test.cpp
@@ -6,10 +6,7 @@ namespace OnBoarding {
 
 KDColor PowerOnSelfTest::Perform() {
   KDColor previousLEDColor = Ion::LED::getColor();
-
-  /* Light up the LED in blue now. If VBlank test fails, we end up in an
-   * infinite loop and the LED will still be lit up in blue. */
-  Ion::LED::setColor(KDColorBlue);
+  KDColor resultColor = KDColorGreen;
 
   // Screen tests
   bool screenTestsOK = Shared::POSTAndHardwareTests::VBlankOK() && Shared::POSTAndHardwareTests::LCDDataOK(k_LCDTestIterationsCount);
@@ -19,12 +16,15 @@ KDColor PowerOnSelfTest::Perform() {
   Ion::Display::pushRectUniform(KDRect(0, 0, Ion::Display::Width, Ion::Display::Height), KDColorWhite);
   Ion::Display::waitForVBlank();
 
+  // Battery test
   if (screenTestsOK) {
-    // Battery test
-    bool batteryTestOK = Shared::POSTAndHardwareTests::BatteryOK();
-    Ion::LED::setColor(batteryTestOK ? KDColorGreen : KDColorRed);
+    if (!Shared::POSTAndHardwareTests::BatteryOK()) {
+      resultColor = KDColorRed;
+    }
+  } else {
+    resultColor = KDColorBlue;
   }
-
+  Ion::LED::setColor(resultColor);
   return previousLEDColor;
 }
 
diff --git a/apps/shared/post_and_hardware_tests.cpp b/apps/shared/post_and_hardware_tests.cpp
index e1661d7e7..944568fdc 100644
--- a/apps/shared/post_and_hardware_tests.cpp
+++ b/apps/shared/post_and_hardware_tests.cpp
@@ -10,10 +10,11 @@ bool POSTAndHardwareTests::BatteryOK() {
 }
 
 bool POSTAndHardwareTests::VBlankOK() {
+  bool result = true;
   for (int i=0; i<3; i++) {
-    Ion::Display::waitForVBlank();
+    result = result && Ion::Display::waitForVBlank();
   }
-  return true;
+  return result;
 }
 
 bool POSTAndHardwareTests::LCDDataOK(int numberOfIterations) {
diff --git a/ion/src/device/shared/drivers/timing.cpp b/ion/src/device/shared/drivers/timing.cpp
index 63564d701..13ee49455 100644
--- a/ion/src/device/shared/drivers/timing.cpp
+++ b/ion/src/device/shared/drivers/timing.cpp
@@ -27,7 +27,7 @@ void usleep(uint32_t us) {
   }
 }
 
-uint64_t millis() {
+volatile uint64_t millis() {
   return MillisElapsed;
 }