THE SHORT ANSWER

HP’s Thunderbolt Dock G4 Features and Troubleshooting white paper starts with authentication, unplug/re-plug, restart and a dock hardware reset (undock, unplug dock power for 5 seconds). SoftPaq release notes for G4 firmware document display fixes: SP153736 external display connection/stability; SP155361 DP distortion/artifacts on AMD hosts and HDMI blink at 1920×1200 or 3440×1440; SP158825 external-monitor distortion. Update dock firmware from HP’s G4 drivers page (One Click / SoftPaq), keep notebook BIOS and graphics current, reseat DP/HDMI cables, and stay inside HP’s documented port combinations. On non-Thunderbolt hosts, enable High Resolution mode in F10 BIOS when 4K@60 is unavailable in multi-function mode. This page maps HP documentation only — not a physical test by NYBreaking.

Manufacturer documentation · Not physically tested by NYBreaking

1. Scope: G4 flickering vs blank screens

This page maps official HP documentation for the HP Thunderbolt Dock G4 family (120W G4 and related G4 SKUs on HP’s SoftPaq pages). It is not a physical lab test and does not invent third-party cable brands as “approved.”

2. Update G4 firmware (HP SoftPaq notes that mention display)

HP’s white paper positions the HP One Click Installer for seamless G4 firmware updates on Windows 10/11 (not Chrome/Linux/macOS in that installer section). SoftPaq pages list concrete display-related FIXES:

  • SP153736 (firmware 1.5.24.0): “Fixes external display connection and stability issues” (plus USB-C monitor and abnormal-shutdown items on that SoftPaq page).
  • SP155361 (firmware 1.5.25.0): Fixes DP monitors that are visually distorted or show artifacts on an AMD host; fixes HDMI that blinks when resolution is set to 1920×1200 or 3440×1440; fixes improper display function on AMD hosts.
  • SP158825 (firmware 1.5.27.0): “Fixes an issue on external monitors connected to the dock that causes the display to be distorted,” among other items. Prefer the latest SoftPaq shown on HP’s G4 drivers page rather than pinning an old build.
  • Download path: HP Thunderbolt Dock 120W G4 Software and Drivers ↗ (or the SoftPaq for your exact G4 SKU). Prerequisites on SoftPaq pages: Windows 10/11 with admin rights; .NET Framework 4.5+. Remove extra USB 3.0 devices except keyboard/mouse during One Click installs per HP’s white paper.
  • Also update notebook BIOS and graphics via HP Image Assistant / HP Support Assistant when HP documents that path for your model — the white paper’s opening note is to run latest drivers, BIOS and firmware for full feature support.

3. Official resets when the image flickers or drops

From HP’s Troubleshooting Issues section (walk steps until resolved):

  1. Ensure the dock authenticated on first connection (white paper First-time Connection).
  2. Unplug and re-plug the dock; restart the notebook.
  3. Dock hardware reset: undock the G4 from the notebook → unplug the dock power cable for 5 seconds → restore power and redock.
  4. If Thunderbolt Controller or Intel USB 3.1 Host Controller shows an error code in Device Manager after a too-fast reinsert: undock, wait 20 seconds, redock; if needed, undock and reboot.
  5. Notebook hardware reset (white paper): power off → remove AC and all USB devices → hold power button 15 seconds → restore power and retest.
  6. Intermittent USB displays missing after restart: re-plug the display or toggle duplicate ↔ extended.

4. Port, cable and resolution limits HP documents

  • HP documents up to four external displays depending on notebook video capability; dual 4K@60 (DP 1.2 hosts) and triple 4K@60 (DP 1.4 DSC hosts) appear in the white paper’s capability tables — stay inside the table for your host mode (Thunderbolt vs multi-function).
  • Mutually exclusive ports: HP notes that bottom DP and Type-C DisplayPort paths can be mutually exclusive for some high-refresh dual-4K setups. Prefer Thunderbolt port + another video port, or both DP ports (with possible refresh drop to 60 Hz) as HP lists.
  • 4K via HDMI/DP-to-USB-C dongle on the dock’s USB-C: known limitation — plug the monitor into native DP/HDMI or the dock Thunderbolt port instead.
  • Non-Thunderbolt host, multi-function mode: if 4K@60 is unavailable, enable High Resolution mode when connected to a USB-C alt mode dock in F10 → Advanced → System Options.
  • HP Support also documents that a USB-C monitor on the dock’s Thunderbolt downstream port may show no content when the dock itself is attached to a non-Thunderbolt computer port with multiple monitors — connect the dock to a Thunderbolt/USB4 host port, or move that monitor to another USB-C port on the dock as HP’s workaround states.
  • HP displays that fail to wake from low power on hot-plug: monitor OSD → Input Control → DP Hot-Plug Detection → Always Active.

5. Practical isolation order (still HP-aligned)

  1. Update G4 firmware to the newest SoftPaq on HP’s drivers page; reboot; dock reset (5-second power pull).
  2. Reseat DP/HDMI cables; try a different certified cable and a different video port on the same dock.
  3. If SoftPaq language matches your symptom (HDMI blink at 1920×1200 / 3440×1440, DP artifacts on AMD, general distortion), confirm that SoftPaq actually applied (One Click / SoftPaq UI shows the new version).
  4. Lower refresh/resolution temporarily only as a diagnostic toward a mode HP’s table supports — then raise again after firmware/BIOS.
  5. If the same monitor is stable on the laptop’s native HDMI/DP but flickers only through the G4 after current firmware, contact HP Support with dock serial / eTag firmware version — do not invent a “must replace” verdict here.

6. Limits and what this page will not claim

  • Forum threads may describe intermittent flicker lasting seconds; those reports are not treated as evidence on this page. Only HP white-paper steps and SoftPaq FIXES are cited.
  • This site does not claim physical reproduction of G4 flicker, cable quality rankings, or non-HP SoftPaqs.
  • After Windows updates that break Thunderbolt stacks broadly, also read Thunderbolt dock not working after a Windows update, then return to HP’s G4 firmware path.

Sources you can inspect

Based on official documentation reviewed 2026-11-06. Steps are general; follow the manual for your exact model. No physical test by NYBreaking. Undocumented third-party dock behavior is not invented here.

Put the conditions into your own setup.

Choose the exact equipment, then save or print the connection checklist.

Open the planner

Found a mismatch? Report a correction. No active paid affiliate links on this page.