diff --git a/loader/LibExt/LIBExt_src/Ctrl_Flow/bl_func.c b/loader/LibExt/LIBExt_src/Ctrl_Flow/bl_func.c
index c40c15e04..90fed45cb 100755
--- a/loader/LibExt/LIBExt_src/Ctrl_Flow/bl_func.c
+++ b/loader/LibExt/LIBExt_src/Ctrl_Flow/bl_func.c
@@ -3218,7 +3218,7 @@ _THUMB2 UINT32 bl_mainFlow(void)
 	}
 
 	UINT32 ota_flag = 0;
-    if(gsfSpecialKeyCallBack(0))
+    if(FALSE == gsfSpecialKeyCallBack(0))
     {
         ota_flag = bl_check_ota_flag(uiOTABufferAddr, uiOTABufferSize);
     }
diff --git a/loader/Project/Model/Src/prj_main.c b/loader/Project/Model/Src/prj_main.c
index e3ff2c7ef..b33b8e7f6 100755
--- a/loader/Project/Model/Src/prj_main.c
+++ b/loader/Project/Model/Src/prj_main.c
@@ -43,8 +43,8 @@
 #define GPIO_SPECIAL_USB D_GPIO_7
 
 #elif (MODEL == MODEL_S550)
-#define GPIO_KEY_TEST P_GPIO_22
-#define GPIO_ISP_KEY_DET C_GPIO_4
+#define GPIO_KEY_TEST P_GPIO_22//Key Up
+#define GPIO_ISP_KEY_DET C_GPIO_4 //Key Left
 #define GPIO_FASTBOOT_KEY GPIO_KEY_TEST
 #define GPIO_SPECIAL_KEY GPIO_KEY_TEST
 #define GPIO_SPECIAL_KEY2 GPIO_ISP_KEY_DET
@@ -158,17 +158,18 @@ static BOOL prj_isSpecialKeyPressed(UINT32 ota_flag)
     #if (MODEL == MODEL_S530)
 	if ((!gpio_getPin(GPIO_SPECIAL_KEY)) && (gpio_getPin(GPIO_SPECIAL_USB)))
     #elif (MODEL == MODEL_S550)
-	if ((gpio_getPin(GPIO_SPECIAL_KEY)) && (gpio_getPin(GPIO_SPECIAL_USB)))
+    if ((!(gpio_getPin(GPIO_SPECIAL_KEY2)) && (gpio_getPin(GPIO_SPECIAL_USB))))//Force Upgrade
     #endif
     {
-		return TRUE;
-	}
-    else if((!(gpio_getPin(GPIO_SPECIAL_KEY2)) && (gpio_getPin(GPIO_SPECIAL_USB))) || prj_is_WDT_OTA() || prj_is_Flash_OTA(ota_flag))
+        return TRUE;
+    }
+    else if(prj_is_WDT_OTA() || prj_is_Flash_OTA(ota_flag))//Software OTA upgrade
     {
         return TRUE;
-    }else {
-		return FALSE;
-	}
+    }else
+    {
+        return FALSE;
+    }
 	//return TRUE;
 }
 static BOOL prj_issfSpecialKeyPressed(UINT32 ota_flag)
@@ -177,7 +178,7 @@ static BOOL prj_issfSpecialKeyPressed(UINT32 ota_flag)
     #if (MODEL == MODEL_S530)
     if ((!gpio_getPin(GPIO_SPECIAL_KEY)) && (gpio_getPin(GPIO_SPECIAL_USB)))
     #elif (MODEL == MODEL_S550)
-    if ((gpio_getPin(GPIO_SPECIAL_KEY)) && (gpio_getPin(GPIO_SPECIAL_USB)))
+    if ((!(gpio_getPin(GPIO_SPECIAL_KEY2)) && (gpio_getPin(GPIO_SPECIAL_USB))))//Force Upgrade
     #endif
     {
         return TRUE;