diff --git a/loader/Project/Model/Src/prj_main.c b/loader/Project/Model/Src/prj_main.c
index 1dd9c1281..b1ca86fcf 100755
--- a/loader/Project/Model/Src/prj_main.c
+++ b/loader/Project/Model/Src/prj_main.c
@@ -115,10 +115,16 @@ static BOOL prj_isSpecialKeyPressed(void)
         debug_msg("GPIO_SPECIAL_KEY2 0\r\n");
     }*/
 
-	if ((!gpio_getPin(GPIO_SPECIAL_KEY)) && (gpio_getPin(GPIO_SPECIAL_USB))) {
+    #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)))
+    #endif
+    {
 		return TRUE;
 	}
-    else if(!(gpio_getPin(GPIO_SPECIAL_KEY2))){
+    else if(!(gpio_getPin(GPIO_SPECIAL_KEY2)))
+    {
         return TRUE;
     }else {
 		return FALSE;