diff --git a/drivers/media/video/msp3400-kthreads.c b/drivers/media/video/msp3400-kthreads.c
index 4c7f85b..e1821eb 100644
--- a/drivers/media/video/msp3400-kthreads.c
+++ b/drivers/media/video/msp3400-kthreads.c
@@ -483,7 +483,6 @@
 			/* no carrier scan, just unmute */
 			v4l_dbg(1, msp_debug, client, "thread: no carrier scan\n");
 			state->scan_in_progress = 0;
-			state->rxsubchans = V4L2_TUNER_SUB_STEREO;
 			msp_set_audio(client);
 			continue;
 		}
@@ -851,12 +850,15 @@
 		source = 1; /* stereo or A|B */
 		matrix = 0x20;
 		break;
-	case V4L2_TUNER_MODE_STEREO:
 	case V4L2_TUNER_MODE_LANG1:
-	default:
 		source = 3; /* stereo or A */
 		matrix = 0x00;
 		break;
+	case V4L2_TUNER_MODE_STEREO:
+	default:
+		source = 3; /* stereo or A */
+		matrix = 0x20;
+		break;
 	}
 
 	if (in == MSP_DSP_IN_TUNER)
@@ -1030,6 +1032,9 @@
 	int is_stereo = status & 0x40;
 	int oldrx = state->rxsubchans;
 
+	if (state->mode == MSP_MODE_EXTERN)
+		return 0;
+
 	state->rxsubchans = 0;
 	if (is_stereo)
 		state->rxsubchans = V4L2_TUNER_SUB_STEREO;