diff --git a/AGENTS.md b/AGENTS.md
index 98e2e58..5e6c45a 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -644,3 +644,14 @@ verify its own source before asking the analyzer to explain the capture.
 - [x] Retry the Tethys browser recording `/start` request to survive transient SSH banner timeouts.
 - [x] Open the manual review capture directory in Dolphin after summarization so copied Tethys captures are immediately inspectable.
 - [ ] Re-run the mirrored probe and confirm the preview is visible/audible before trusting any pairing diagnosis.
+
+## 0.17.35 Right-Eye Capture Diagnostics Checklist
+
+Context: manual Tethys testing showed the desktop was awake and HDMI was on, but the right-eye feed stayed black. Server logs showed `eye=r` reached `PLAYING` and then hit a V4L2/GStreamer `Invalid argument (22)` poll error before any frame was pushed, while the left eye streamed normally.
+
+- [x] Confirm Tethys was not asleep: X11 reported HDMI connected at 1920x1080 and `Monitor is On`.
+- [x] Remove stale Tethys browser-probe processes after mirrored probe runs so manual Google Meet testing does not compete with old recorder sessions.
+- [x] Propagate late eye-capture GStreamer bus errors into the gRPC video stream so the launcher reports a preview stream error instead of a silent black window.
+- [x] Add a first-frame watchdog for eye capture streams so opened-but-empty sources surface as explicit diagnostics.
+- [ ] Re-run a manual two-eye session and confirm right-eye failures now appear in the session log with the concrete source error.
+- [ ] If `eye-r` still reports `poll error ... EINVAL`, recover/reseat the right HDMI capture path or add a dedicated eye-capture soft recovery path separate from UVC/UAC.
diff --git a/Cargo.lock b/Cargo.lock
index f6fd258..d459319 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1652,7 +1652,7 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "lesavka_client"
-version = "0.17.34"
+version = "0.17.35"
 dependencies = [
  "anyhow",
  "async-stream",
@@ -1686,7 +1686,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_common"
-version = "0.17.34"
+version = "0.17.35"
 dependencies = [
  "anyhow",
  "base64",
@@ -1698,7 +1698,7 @@ dependencies = [
 
 [[package]]
 name = "lesavka_server"
-version = "0.17.34"
+version = "0.17.35"
 dependencies = [
  "anyhow",
  "base64",
diff --git a/client/Cargo.toml b/client/Cargo.toml
index 266d8e8..36cbf0a 100644
--- a/client/Cargo.toml
+++ b/client/Cargo.toml
@@ -4,7 +4,7 @@ path                    = "src/main.rs"
 
 [package]
 name                    = "lesavka_client"
-version                 = "0.17.34"
+version                 = "0.17.35"
 edition                 = "2024"
 
 [dependencies]
diff --git a/common/Cargo.toml b/common/Cargo.toml
index 08473e9..e6925c9 100644
--- a/common/Cargo.toml
+++ b/common/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name                    = "lesavka_common"
-version                 = "0.17.34"
+version                 = "0.17.35"
 edition                 = "2024"
 build                   = "build.rs"
 
diff --git a/server/Cargo.toml b/server/Cargo.toml
index 1a74cda..950f843 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -10,7 +10,7 @@ bench                   = false
 
 [package]
 name                    = "lesavka_server"
-version                 = "0.17.34"
+version                 = "0.17.35"
 edition                 = "2024"
 autobins                = false
 
diff --git a/server/src/video/eye_capture.rs b/server/src/video/eye_capture.rs
index 06e395a..8f3a6e1 100644
--- a/server/src/video/eye_capture.rs
+++ b/server/src/video/eye_capture.rs
@@ -172,9 +172,11 @@ pub async fn eye_ball_with_request(
     let queue_peak_depth = Arc::new(AtomicU32::new(0));
     let last_telemetry_sec = Arc::new(AtomicU64::new(0));
     let packet_seq = Arc::new(AtomicU64::new(0));
+    let first_sample_seen = Arc::new(AtomicBool::new(false));
 
     let queue_buffers = env_u32("LESAVKA_EYE_QUEUE_BUFFERS", 4).max(1);
     let appsink_buffers = env_u32("LESAVKA_EYE_APPSINK_BUFFERS", 4).max(1);
+    let first_frame_timeout_ms = env_u32("LESAVKA_EYE_FIRST_FRAME_TIMEOUT_MS", 5_000).max(500);
     let keyframe_interval = env_u32("LESAVKA_EYE_KEYFRAME_INTERVAL", request.fps.clamp(1, 5))
         .clamp(1, request.fps.max(1));
     let use_test_src =
@@ -225,6 +227,7 @@ pub async fn eye_ball_with_request(
 
     let chan_capacity = env_usize("LESAVKA_EYE_CHAN_CAPACITY", 32).max(8);
     let (tx, rx) = tokio::sync::mpsc::channel(chan_capacity);
+    let tx_for_bus = tx.clone();
 
     if let Some(src_pad) = pipeline
         .by_name(&format!("cam_{eye}"))
@@ -252,6 +255,7 @@ pub async fn eye_ball_with_request(
     let last_telemetry_sec_for_cb = Arc::clone(&last_telemetry_sec);
     let server_encoder_label_for_cb = server_encoder_label.clone();
     let server_process_cpu_tenths_for_cb = Arc::clone(&server_process_cpu_tenths);
+    let first_sample_seen_for_cb = Arc::clone(&first_sample_seen);
     sink.set_callbacks(
         gst_app::AppSinkCallbacks::builder()
             .new_sample(move |sink| {
@@ -259,6 +263,7 @@ pub async fn eye_ball_with_request(
                 let buffer = sample.buffer().ok_or(gst::FlowError::Error)?;
                 let map = buffer.map_readable().map_err(|_| gst::FlowError::Error)?;
                 let is_idr = contains_idr(map.as_slice());
+                first_sample_seen_for_cb.store(true, Ordering::Relaxed);
 
                 static FRAME: AtomicU64 = AtomicU64::new(0);
                 let frame = FRAME.fetch_add(1, Ordering::Relaxed);
@@ -406,7 +411,21 @@ pub async fn eye_ball_with_request(
 
     let bus = pipeline.bus().expect("bus");
     start_eye_pipeline(&pipeline, &bus, eye)?;
-    let bus_watch = BusWatchHandle::spawn(bus, eye.to_owned());
+    let first_sample_seen_for_watchdog = Arc::clone(&first_sample_seen);
+    let tx_for_first_frame_watchdog = tx_for_bus.clone();
+    let first_frame_eye = eye.to_string();
+    tokio::spawn(async move {
+        sleep(Duration::from_millis(first_frame_timeout_ms as u64)).await;
+        if !first_sample_seen_for_watchdog.load(Ordering::Relaxed) {
+            let detail = format!(
+                "eye-{first_frame_eye} capture produced no frames within {first_frame_timeout_ms} ms"
+            );
+            let _ = tx_for_first_frame_watchdog
+                .send(Err(Status::internal(detail)))
+                .await;
+        }
+    });
+    let bus_watch = BusWatchHandle::spawn(bus, eye.to_owned(), tx_for_bus);
 
     Ok(VideoStream {
         _pipeline: pipeline,
diff --git a/server/src/video/stream_core.rs b/server/src/video/stream_core.rs
index 86c6be2..8df8c93 100644
--- a/server/src/video/stream_core.rs
+++ b/server/src/video/stream_core.rs
@@ -80,7 +80,11 @@ struct BusWatchHandle {
 
 #[cfg(not(coverage))]
 impl BusWatchHandle {
-    fn spawn(bus: gst::Bus, eye: String) -> Self {
+    fn spawn(
+        bus: gst::Bus,
+        eye: String,
+        stream_errors: tokio::sync::mpsc::Sender<Result<VideoPacket, Status>>,
+    ) -> Self {
         let alive = Arc::new(AtomicBool::new(true));
         let alive_flag = Arc::clone(&alive);
         let join = std::thread::spawn(move || {
@@ -97,6 +101,12 @@ impl BusWatchHandle {
                             err.error(),
                             err.debug().unwrap_or_default()
                         );
+                        let detail = format!(
+                            "eye-{eye} capture pipeline error: {} ({})",
+                            err.error(),
+                            err.debug().unwrap_or_default()
+                        );
+                        let _ = stream_errors.blocking_send(Err(Status::internal(detail)));
                         break;
                     }
                     Warning(warning) => {