DIAGNOSTIC
PLAYBOOK.
Troubleshoot in signal-chain order. Do not change five devices at once: establish a known-good baseline, change one variable, and read the Vertex signal information after each change.
GOLDEN RULE
Source → display directly first. Then Source → Vertex → display in basic HDR10. Only after that add LLDV EDID, AVR/soundbar, scaling or a second display.
Source → display directly first. Then Source → Vertex → display in basic HDR10. Only after that add LLDV EDID, AVR/soundbar, scaling or a second display.
No picture after selecting an LLDV EDID
- Return the source to a conservative 4K60-or-lower HDMI 2.0 mode.
- Confirm the display's enhanced/expanded HDMI mode is enabled.
- Restore a known-good Vertex EDID and establish picture.
- Select the LLDV EDID again (EDID MANAGER → CUSTOM → your slot; this sends a hot-plug), or use CONFIG → ISSUE HOTPLUG / a short press on RST; pull the source's power cord if needed.
- Read Vertex input/output signal information. Separate an EDID problem from a downstream display problem.
Dolby Vision option is missing
- Verify the exact source hardware supports Dolby Vision.
- Confirm Vertex is advertising the intended DV/LLDV capability.
- Check whether an AVR/switch between source and Vertex is replacing EDID.
- For Shield, inspect Display & Sound → Dolby Vision / Custom display mode.
- For Apple TV, inspect Video and Audio and test the advertised format.
Picture is magenta / green / badly colored
- Return color space/chroma settings to Auto where possible.
- Verify the display input is in its enhanced 4K/HDR mode.
- Check Vertex input versus output color format and bit depth.
- Remove scaling/conversion temporarily.
- Return to HDR10; if HDR10 is correct and only the LLDV path fails, investigate EDID/DV and display HDR presentation rather than cabling first.
Image is too dark in LLDV
- Confirm the projector is actually using the intended HDR picture mode.
- Do not compensate first with extreme brightness/contrast changes.
- Verify the LLDV EDID/luminance strategy matches the projector workflow.
- Compare the same scene with normal HDR10.
- Only then tune the projector's HDR curve/level.
Random black screens when starting a movie
- Determine whether it happens only during frame-rate/dynamic-range changes. Apple and Roku both document temporary blanking during HDMI mode switching.
- If it never recovers, test a fixed resolution/refresh rate.
- Check cable quality and length, especially near 18Gbps modes.
- Remove AVR/switch stages temporarily.
- Read the Vertex signal before and after the failure.
4K works but HDR does not
- Enable the TV/projector's enhanced/expanded HDMI input mode.
- Samsung: Input Signal Plus. Epson TW9400/5050UB: EDID Expanded. Other brands: use the exact model manual.
- Confirm the source sees HDR capability through Vertex.
- Check that the requested format stays inside the original Vertex 18Gbps envelope.