NanoKVM PCIe (UE revision): no video — lt6911_probe CVI_FAILURE / data:ffffffff, identical on app 2.4.3 and 2.2.9, survives cold power cycle

[RealKomander]

Summary

On a NanoKVM PCIe whose board is detected as the "UE" capture-chip revision, video capture
fails completely. The web UI is stuck on "Switching resolution…" indefinitely. The LT6911 I²C
probe returns no response (ffffffff) and the backend reports Cannot obtain HDMI input.

It worked normally before an application update. The failure is identical on two different app
versions and persists across a full cold power cycle, which points at the firmware-level capture
driver vs. this hardware revision rather than the application.

Environment

• Model: NanoKVM PCIe
• Board revision: UE (reported by nanokvm_update_edid, see below)
• Image version: v1.4.1
• Application version: 2.4.3 (also reproduced on 2.2.9)
• Host: server with HDMI connected directly (GPU -> NanoKVM), known-good cable, source outputting 1920x1080
• Network: device on LAN, web UI + SSH reachable

Symptom

• Web UI: permanent "Switching resolution…", no frames.
• Capture detects resolution correctly:
  • cat /kvmapp/kvm/width -> 1920
  • cat /kvmapp/kvm/height -> 1080
• Services healthy: kvm_system and NanoKVM-Server both running; port 80 listening.
• Sensor config is the stock LT template (/mnt/data/sensor_cfg.ini == sensor_cfg.ini.LT):
  name = LONTIUM_LT6911_2M_60FPS_8BIT, sns_i2c_addr = ff.

Key log output (NanoKVM-Server / vision init)

[sensor_prob = lt6911_probe]

[lt6911_i2c_write] : addr = ee. data = 1

[lt6911_i2c_read]  : addr = 0

...

[lt6911_probe] jump return nVal -198

data:ffffffff ffffffff

[lt6911_probe] jump return CVI_FAILURE -206

...

[kvmv] Cannot obtain HDMI input

[error] [cgo.go:85] failed to read kvm image: -4   (repeats continuously)

The I²C read returns ffffffff (no device response), so the probe fails and no frames are produced.

(Note: the sensorName(0) mismatch, mwSns:6911 != pqBinSns:4653 line also appears, but I understand
that is benign and present on working units: flagging it only so it isn't mistaken for the cause.)

EDID tool output (shows board revision)

/kvmapp/system/tool/nanokvm_update_edid /kvmapp/system/tool/E21_NanoKVM.bin
Chip Version Error: UE version's edid can't be updated

The bundled E21_NanoKVM.bin targets LT6911UXC; this board reports as "UE", so the EDID tool refuses.

Steps to reproduce

1. NanoKVM PCIe, board reporting as UE revision, image v1.4.1.
2. Update/run application 2.4.3 (also tested 2.2.9).
3. Connect a 1080p HDMI source; open web UI.
4. Video never appears; logs show the probe failure above.

Expected vs. actual

• Expected: LT6911 probe succeeds, HDMI input captured, video shown.
• Actual: probe returns ffffffff / CVI_FAILURE, Cannot obtain HDMI input, no video.

What I've already ruled out

• Application version: identical failure on 2.4.3 and 2.2.9 (clean full /kvmapp swap, matched to v1.4.x), so not app-side.
• Sensor config: active config is byte-identical to the stock .LT template.
• Transient chip latch: full cold power cycle (host powered off, cord removed ~5 min) does not clear it.
• Network/firewall/browser: services up, port 80 listening; failure is upstream of streaming (capture never produces a frame).
• Cabling/source: same setup worked before the update; width/height are detected correctly (1920x1080).

Hypothesis / request

This looks like the v1.4.1 firmware lt6911 driver not matching the UE capture-chip revision,
causing the I²C probe to fail. Since the driver ships in the firmware image (not /kvmapp),
downgrading the app cannot fix it. Could you confirm:

1. Which image/firmware version supports the UE PCIe revision?
2. Is there a UE-specific image, or a fix for the LT6911 probe on UE boards?

Happy to provide full boot logs, dmesg, or run any diagnostics. Thanks!

[RealKomander]

Used balena etcher to install 1.4.3, everything works now. Good luck to those without a micro sd adapter...