diff --git a/src/ersky9x/diskio.c b/src/ersky9x/diskio.c
index d47e97b31..42cae763e 100644
--- a/src/ersky9x/diskio.c
+++ b/src/ersky9x/diskio.c
@@ -854,9 +854,10 @@ void sdPoll10mS()
       break;
 
     case SD_ST_DATA:
-      f_mount(0, &g_FATFS_Obj);
-      retrieveAvailableAudioFiles();
-      Card_state = SD_ST_MOUNTED;
+      if (f_mount(0, &g_FATFS_Obj) == FR_OK) {
+        retrieveAvailableAudioFiles();
+        Card_state = SD_ST_MOUNTED;
+      }
       break;
 
     case SD_ST_ERR:
@@ -901,13 +902,21 @@ void sdInit()
 
   sdCmd9();
   sdCmd7(); // Select Card
+
+  CoTickDelay(1);  // 2ms
+
   sdAcmd51();
   sdAcmd6(); // Set bus width to 4 bits, and speed to 9 MHz
 
-  // Should check the card can do this ****
-  f_mount(0, &g_FATFS_Obj);
-  retrieveAvailableAudioFiles();
+  CoTickDelay(1);  // 2ms
 
+  // Should check the card can do this ****
+  if (f_mount(0, &g_FATFS_Obj) != FR_OK) {
+    Card_state = SD_ST_DATA;
+    return;
+  }
+
+  retrieveAvailableAudioFiles();
   Card_state = SD_ST_MOUNTED;
 }