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MODEL-SPECIFIC DIAGNOSTIC

Diagnostics / BenQ / RP04

No image through USB-C

A USB-C cable is connected, but the RP04 does not display the computer image.

Applies to this documented familyRP6504, RP7504, RP8604

Likely causes, most useful checks first

  • The computer port does not support DisplayPort Alt Mode.
  • The cable carries charging/data but not video.
  • The wrong input is selected.
  • A dock or adapter is failing.

Safe checks

01

Select the USB-C input

Use the panel input menu to select the USB-C source explicitly.

What the result means: If the image appears, no hardware repair is required.

02

Verify video-capable USB-C

Check the computer specification for DisplayPort Alt Mode or Thunderbolt video support.

What the result means: A charge-only or data-only USB-C port cannot provide the expected image.

03

Use a known-good video-rated cable

Test a short USB-C cable explicitly rated for video and bypass any dock.

What the result means: If this works, replace the cable or investigate the dock.

Sources

Reviewed under the BoardFaults safe-external-check policy · risk class: low · updated 2026-09-03