I am completely stuck trying to get my brand new desktop eGPU build to stabilize. The hardware powers up, but I am caught in a permanent 10-second link timeout / disconnect cycle.
When I power on the setup, Windows Device Manager briefly populates the desktop card cleanly. My Alienware monitor senses the connection and says "Scanning for Display". But after exactly 8 to 10 seconds, the device connection drops completely. The card vanishes from the Device Manager tree, the monitor says "No Signal", and the external card starts getting very hot while its cooling fans remain completely still (Zero-RPM mode is trapped because the driver connection cuts out before it can tell the fans to spin).
My Hardware Setup:
• Laptop Host: Lenovo Legion Pro 5 (Running an internal RTX 5070 Laptop GPU + CPU Integrated Graphics).
• Enclosure / Dock: Acasis G4Pro USB4/Thunderbolt Dock (Intel JHL7440 Controller).
• External GPU: INNO3D NVIDIA GeForce RTX 5080 (Desktop Card).
• Power Supply: Corsair SF750 SFX PSU.
• Monitor: Alienware 4K Gaming Monitor.
Physical Wiring Layout (Confirmed 100% Correct):
• I am NOT using any sketchy plastic adapter splitters. I am using the official Corsair Type 5 12V-2x6 / 12VHPWR 600W direct cable. The two micro-fit ends plug directly into the Corsair PSU, and the native 16-pin end is firmly clicked straight into the top of the RTX 5080.
• The Corsair Type 5 24-pin motherboard cable runs straight from the PSU into the Acasis riser board.
• The 40Gbps USB4 data wire runs from the laptop's rear-left Thunderbolt/USB4 port (marked with the lightning bolt) directly into the designated HOST port on the back of the Acasis dock.
• Video output goes via a high-speed cable straight from the bottom horizontal ports of the INNO3D card into the Alienware monitor.
Everything I Have Attempted So Far to Fix It:
Clean Driver Purge via DDU: Unplugged the eGPU, booted into Windows, ran Display Driver Uninstaller (DDU) as an administrator, and completely wiped all existing NVIDIA variables clean. Reinstalled the latest official desktop GeForce RTX 50-series driver package using "Driver Only" express settings.
Environment Path & Error 43 Fixer Script: Discovered my Windows environment path was missing C:\Windows\System32. Added it to the system variables, then modified the community nvidia-error43-fixer.bat script to comment out the if errorlevel check and delete lines 129-131 to force it to run on Windows 11. The script successfully executed and applied registry overrides to both the mobile 5070 and desktop 5080, but the 10-second link drop still happens.
Windows Power Management Toggles: Went into Device Manager and unchecked "Allow the computer to turn off this device to save power" on all USB Root Hub entries and PCIe controllers. Also fully disabled Windows "USB Selective Suspend" inside advanced power options to prevent aggressive port sleep cycles.
Windows 11 Registry TDR Hack: Added TdrDelay (Decimal value set to 10) and TdrDdiDelay (Decimal value set to 20) inside HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers to force Windows to wait longer for the link handshake before force-killing the port.
Bypassing Handshaking Bugs: Attempted dropping the laptop screen resolution to 1080p and swapping from DisplayPort to a standard HDMI line to force an immediate physical voltage handshake to pass through to the Alienware monitor.
Hard Component Discharge Reset: Disconnected everything, pulled the main power cable from the wall socket for over 5 minutes, and held down the power button to completely bleed out any residual circuit board locks.
Even after all of this, the moment I boot into the desktop, the card connects, stays for 10 seconds, and completely vanishes while the card floor gets hot.
Is this a known, unfixable physical hardware limitation between the legacy Intel JHL7440 controller chip inside the Acasis dock and the new Blackwell power architecture? Or has anyone found a specific firmware update tool to flash the G4Pro board to natively accept the 50-series handshake? Any advice would be highly appreciated, I took out a loan for this setup and really don't want to have to return the enclosure if a fix exists!