diff --git a/tests/features/test_gamma.py b/tests/features/test_gamma.py
index e46701d..875f28c 100644
--- a/tests/features/test_gamma.py
+++ b/tests/features/test_gamma.py
@@ -122,6 +122,28 @@ def test_identify_getramp_fails():
                 assert identify_display(r"\\.\DISPLAY1") is False
 
 
+def test_identify_flash_fails():
+    from winrandr.features.gamma import identify_display
+
+    with patch("winrandr.features.gamma._CreateDCW", return_value=0x1234):
+        with patch("winrandr.features.gamma._GetDeviceGammaRamp", return_value=1):
+            with patch("winrandr.features.gamma._SetDeviceGammaRamp", side_effect=[0, 1]):
+                with patch("winrandr.features.gamma._DeleteDC"):
+                    with patch("winrandr.features.gamma.time.sleep"):
+                        assert identify_display(r"\\.\DISPLAY1") is False
+
+
+def test_identify_blank_fails():
+    from winrandr.features.gamma import identify_display
+
+    with patch("winrandr.features.gamma._CreateDCW", return_value=0x1234):
+        with patch("winrandr.features.gamma._GetDeviceGammaRamp", return_value=1):
+            with patch("winrandr.features.gamma._SetDeviceGammaRamp", side_effect=[1, 0, 1]):
+                with patch("winrandr.features.gamma._DeleteDC"):
+                    with patch("winrandr.features.gamma.time.sleep"):
+                        assert identify_display(r"\\.\DISPLAY1") is False
+
+
 def test_identify_exception():
     from winrandr.features.gamma import identify_display
 
diff --git a/winrandr/features/gamma.py b/winrandr/features/gamma.py
index 2c9eefa..d285020 100644
--- a/winrandr/features/gamma.py
+++ b/winrandr/features/gamma.py
@@ -87,6 +87,7 @@ def identify_display(device_name: str, duration: float = 2.0) -> bool:
         return False
 
     saved = (c_uint16 * (3 * 256))()
+    all_ok = True
     try:
         ramp = (c_uint16 * (3 * 256))()
         if not _GetDeviceGammaRamp(dc, ramp):
@@ -102,11 +103,17 @@ def identify_display(device_name: str, duration: float = 2.0) -> bool:
 
         interval = duration / 6
         for _ in range(3):
-            _SetDeviceGammaRamp(dc, flash)
+            if not _SetDeviceGammaRamp(dc, flash):
+                logger.warning("设置 %s 闪烁白屏失败（伽马写入被拒绝）", device_name)
+                all_ok = False
+                break
             time.sleep(interval)
-            _SetDeviceGammaRamp(dc, blank)
+            if not _SetDeviceGammaRamp(dc, blank):
+                logger.warning("设置 %s 闪烁黑屏失败（伽马写入被拒绝）", device_name)
+                all_ok = False
+                break
             time.sleep(interval)
     finally:
         _SetDeviceGammaRamp(dc, saved)
         _DeleteDC(dc)
-    return True
+    return all_ok