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Display and Gamescope Problems

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jerrymares edited this page Jul 22, 2026 · 1 revision

Display and Gamescope problems

“Black screen” is a symptom shared by several different failures. First determine whether the Deck, the game, Gamescope, the GPU, and the physical panel are still alive.

Symptom classes

Symptom Leading branches
Backlight on, sound/input/rendering continue physical scanout, plane transition, eDP/TCON/cable
Backlight off or brightness actually zero panel/backlight/power/modeset state
Game frozen and sound loops/stops game, Proton, GPU timeout/reset, OOM
Returned to Library/login repeatedly game or Gamescope crash/session restart
External monitor works, internal panel fails eDP/panel-specific path
Internal panel works, docked display fails dock/cable/monitor/DP Alt Mode/modeset
Desktop Mode wake only KDE/Wayland/resume/display state
First power-on after days off; immediate second boot works cold-start/firmware/panel initialization branch

The last row has its own long-off startup blackout protocol. It is not evidence for the Gamescope forced-composition fix, especially when reported on Windows or OLED.

Capture while black

From SSH or a usable terminal:

sudo ./deckdoc.sh --display-black

Record whether:

  • the backlight is visibly on;
  • audio and controls continue;
  • a recording/stream shows advancing frames;
  • an external display changes the symptom;
  • the event followed wake, app transition, overlay toggle, dock/undock, or update.

Do not change brightness, write bl_power, force a GPU reset, or suspend again before capture.

Interpret the display section

LIVE_RENDER_TO_PHYSICAL_SCANOUT_GAP

DeckDoc found connected eDP, a readable EDID, nonzero LCD backlight, and an active CRTC while the user declared the panel physically black. When a recording also shows valid frames and there is no matching GPU/app crash, the failure boundary moves downstream toward plane commit, DCN/eDP scanout, panel timing, TCON, cable, or panel.

Multiple planes are not an error by themselves. They justify a reversible forced-composition test only for this complete signature. Follow Screen black while sound works.

PANEL_OR_MODESET_STATE_INCOMPLETE

At least one panel prerequisite failed. Forced composition is not automatically indicated. Inspect the missing eDP, EDID, backlight, or CRTC state and correlate kernel modeset/reset errors.

GPU or Gamescope evidence

  • amdgpu_job_timedout, reset, or VM fault: use Crashes, GPU and memory.
  • current-boot Gamescope core dump or repeated restart: inspect the crash/session branch.
  • MangoApp FDINFO_PERMISSION_ABORT: an overlay helper failed; do not automatically label it a compositor crash or panel failure.

Docked/external display branch

DeckDoc lists connectors but does not diagnose the whole dock chain. Preserve both docked and undocked reports, then test one known-good variable at a time: monitor input, cable, adapter/dock, USB-C port, resolution/refresh setting, and power supply. A successful undocked test narrows the path but does not identify which dock component failed.

Use Valve's Docking the Steam Deck guidance for official first steps.

Escalate when

  • the panel is black with missing EDID/eDP or zero backlight;
  • forced composition does not help or one plane was already active;
  • the issue recurs across clean boots and channels with third-party tools disabled;
  • an external/internal split strongly suggests a hardware path;
  • there are GPU reset failures, persistent display-engine errors, or physical damage.

Attach the relevant display, GPU, Gamescope, coredump, ACPI, and exact incident-time excerpts. Linux's amdgpu documentation recommends dmesg and pre/post-reproduction display debug state for DC problems.

References

DeckDoc records evidence before action. Preserve the incident, change one variable at a time, verify the result, and use Steam Support for safety, warranty, and hardware concerns.

DeckDoc diagnostic center

Problems

Recovery and reference

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