diff --git a/src/Controller/DeviceImageController.php b/src/Controller/DeviceImageController.php
index 6d6c67e..bb659f4 100644
--- a/src/Controller/DeviceImageController.php
+++ b/src/Controller/DeviceImageController.php
@@ -90,21 +90,23 @@ class DeviceImageController extends AbstractController
         $currentImageId = (int) $request->headers->get('X-Current-Image-Id', '-1');
         $device->markSeen();
 
-        // TEMP: power-monitor — surface the firmware's previous-cycle
-        // telemetry (awake duration + panel-init time) so we can see
-        // whether the PIN_PWR rail cut affects either. Logged on every
-        // poll; greppable via `device.poll.power_telemetry`. Remove
-        // alongside the firmware's NVS_KEY_PREV_* writes once validated.
-        $prevAwakeMs     = $request->headers->get('X-Prev-Awake-Ms');
-        $prevPanelInitMs = $request->headers->get('X-Prev-Panel-Init-Ms');
-        if ($prevAwakeMs !== null || $prevPanelInitMs !== null) {
-            $this->logger->info('device.poll.power_telemetry', [
-                'mac'                => $mac,
-                'prev_awake_ms'      => $prevAwakeMs,
-                'prev_panel_init_ms' => $prevPanelInitMs,
-                'boot_reason'        => $request->headers->get('X-Boot-Reason'),
-            ]);
-        }
+        // TEMP: power-monitor — log every poll with the firmware-side
+        // headers we care about, even when they're absent, so we can
+        // tell whether the firmware is sending them at all vs. the
+        // controller filtering them out. Greppable via
+        // `device.poll.power_telemetry`. Remove alongside the firmware's
+        // NVS_KEY_PREV_* writes once validated.
+        $this->logger->info('device.poll.power_telemetry', [
+            'mac'                => $mac,
+            'prev_awake_ms'      => $request->headers->get('X-Prev-Awake-Ms'),
+            'prev_panel_init_ms' => $request->headers->get('X-Prev-Panel-Init-Ms'),
+            'boot_reason'        => $request->headers->get('X-Boot-Reason'),
+            'all_x_headers'      => array_filter(
+                $request->headers->all(),
+                static fn(string $name): bool => str_starts_with(strtolower($name), 'x-'),
+                ARRAY_FILTER_USE_KEY,
+            ),
+        ]);
 
         // Auto-correct Device.model from the firmware's X-Panel-Id header. New
         // Devices are created with the default V1 model (see Device entity), so