Why this exists
The LCD6-HD is designed around Phanteks' Windows software, but this workstation runs Ubuntu as its daily operating system. The goal is direct Linux control without keeping Windows or NexLinq in the loop, ultimately turning the display into a persistent live dashboard for CPU, GPU, fan, and pump data.
Rather than guess at undocumented commands, the work was done by inspecting the official software, capturing real USB traffic, and reproducing the transactions from Linux one step at a time.
Confirmed device details
- Product: Phanteks LCD6-HD
- USB VID:PID: 1f3a:6502
- USB 2.0 High Speed composite device
- Interface 0: vendor-specific bulk endpoints
- Interface 1: HID interrupt endpoints
- HID report ID: 0x01
- Observed report sizes: 1024-byte OUT, 512-byte IN
Protocol milestones
0x22 — Device information
A read-only device-information request returns product and firmware metadata.
0x21 — Telemetry
NexLinq sends periodic host telemetry containing temperatures, fan values, timestamps, and other sensor data used by diagnostic layouts.
0x2A — LCD configuration
Sets display configuration such as layout, brightness, orientation, background mode, flags, and fallback color.
0x28 — JPEG transfer
Transfers a full-screen JPEG as acknowledged HID pages. The official Windows software converts supported source images into the display-ready JPEG stream before upload.
0x30 — Layout activation
The final activation packet was the key missing piece in the Linux implementation.
Changing only that final byte in the six-byte prefix turned a fully acknowledged-but-inactive upload into a visible Linux-controlled screen.
Firmware finding
The unit initially reported firmware V1.0.0.0, built December 16, 2025. With that firmware, both reconstructed Linux transactions and official Windows NexLinq screen changes could complete over USB without producing the expected visible result.
After updating through the official Phanteks software, the LCD reported V1.0.0.10, built August 6, 2026, and screen control began working correctly in Windows.
With the new firmware installed, the corrected Linux activation packet successfully displayed the uploaded test image.
Important: this project documents observed protocol behavior; it does not redistribute Phanteks firmware or firmware-update payloads.
Known-good Linux sequence
The first confirmed Linux-controlled image was a deliberately obvious test card reading “Pwned, sucka”. All 172 JPEG packets were acknowledged, and the corrected 0x30 activation immediately switched the LCD to the uploaded image.
Acknowledgements
NexTuxLinq by anoraknophobia targets the Phanteks Matrix900 rather than the LCD6-HD, so its packets and device-specific implementation are not directly reused here. Its protocol notes were nevertheless an important methodological reference: capture the official Windows traffic, verify acknowledgements, change one variable at a time, and avoid guessing at firmware/reset/bootloader commands.
That disciplined workflow directly influenced how the LCD6-HD investigation was conducted and helped keep the reverse-engineering process evidence-driven and safe.
What comes next
- Rerun and harden the cleaned public Linux transport.
- Reproduce the live diagnostics/layout path.
- Feed native Ubuntu CPU and GPU telemetry to the display.
- Add dual-RTX-3090 temperature monitoring.
- Add fan and pump telemetry where available.
- Grow the public protocol notes and examples as each path is validated.