Start with evidence
Run the tests that separate the likely branches
USB-C Display Path Readiness CheckCheck four documented prerequisites for sending video through USB-C, Thunderbolt, a dock, cable or adapter to a display.
Run →Screen Resolution TestShow browser viewport, screen dimensions, and device pixel ratio.
Run →Display Raw Bandwidth CalculatorEstimate raw uncompressed pixel data rate from resolution and refresh rate.
Run →Decision table
What the observation changes
ObservationWhat it meansNext action
Direct USB-C display worksThe laptop's basic DisplayPort path is functioning.Focus on dock upstream cable, firmware and display topology.
Dock USB devices work but display does notUSB data is proven but video lanes/topology are not.Check the dock's supported display mode and cable.
Neither Thunderbolt port drives a known-good direct displayA laptop-side display/port issue remains possible.Run HP diagnostics and update/check supported firmware before service.
Sequence
Work from reversible checks to escalation
- 01
Test the monitor directly from the Spectre first.
- 02
Use a known full-featured Thunderbolt/USB-C cable.
- 03
Confirm monitor input and reduce to one display.
- 04
Reconnect the dock only after direct video is proven.
Likely areas
Keep these branches separate
Upstream cableDock display capabilityMonitor input/cableDisplayPort negotiationPort/firmware
Repair boundary
When to stop changing settings
If both Thunderbolt ports fail with known-good direct DisplayPort paths, use HP diagnostics/support.