What's going on

When a BenQ monitor plays sound through its integrated speakers or audio passthrough port while keeping the display black, it indicates that the monitor is successfully handshaking with your computer. The PC is transmitting a complete DisplayPort or HDMI signal, and the monitor's main logic controller is alive enough to decode audio streams.

The breakdown is happening downstream in the display pipeline: either the LED backlights are not receiving power, the driver board has blown a surface-mount fuse, or the panel's T-Con board is failing to drive the liquid crystal pixels.

Symptoms people notice

• Background music, game sound, or Windows notification chimes play clearly through the monitor.
• The status LED indicator stays solid white or blue (indicating active video input) rather than orange or standby.
• The display backlight remains totally unlit, or flickers once at startup before dropping to pitch black.
• Pressing the menu button yields no visible On-Screen Display (OSD) menu.
• Replugging video cables produces the Windows "device connected" chime, but no video appears.

Likely causes

Audio-without-video issues on desktop displays usually point to distinct hardware power stages. You can read more about broad display failures across our monitor problems hub.

1. Dead LED Backlight Array: A single shorted or open LED in the edge-lit or direct-lit strip breaks the circuit, causing the backlight driver to enter protection shutdown.
2. Blown LED Driver Circuit / Fuse: BenQ power supply boards feature dedicated surface-mount fuses for the backlight circuit that can blow during voltage spikes.
3. T-Con Board Failure: The Timing Controller board converts digital signals into panel row/column voltages. If it loses power, the backlight may turn on, or the panel may stay entirely dark while audio plays through the main board.
4. Display Rate Mismatch: A high refresh rate (e.g., 144Hz/240Hz on Mobiuz or ZOWIE models) set in software that the monitor scalar temporarily fails to sync with.

Quick checks first

Before assuming the internal hardware is fried, work through these initial isolation steps:

• The Flashlight Inspection: Direct a bright flashlight against the screen while playing video. If you see desktop outlines, your LCD panel is rendering video, but the backlight system is completely dead.
• Cable Swap Test: Swap from DisplayPort to HDMI (or vice versa). HDMI and DisplayPort handle audio/video clocking differently on BenQ scalars.
• Test on Another System: Plug the monitor into a laptop or console. If image returns, clear your PC graphics driver settings using Display Driver Uninstaller (DDU).

When it's a real hardware fault

If the flashlight test reveals faint desktop icons, or if the screen stays pitch dark and the OSD menu refuses to render under any circumstance, the fault lies within internal components:

• Backlight LED Strips: Over time, thermal cycling degrades individual LEDs on the substrate board.
• Internal Power Board Capacitors/Fuses: BenQ power supply boards combine AC-to-DC conversion and LED driving; power rail failures disable high-voltage output while leaving 5V/12V logic power intact for audio.
• Panel Ribbon Cables (FFC): Internal flexible flat cables connecting the mainboard to the panel assembly can corrode or loosen.

Soft resets vs board/panel work

Soft resets (unplugging power, resetting resolution via Windows) resolve scalar logic hangups and GPU handshaking failures. These should always be performed first.

Opening the monitor enclosure to replace backlight LED strips, swap T-Con boards, or solder micro-fuses carries high risk. Modern high-refresh BenQ displays use fragile bezel-less panel assemblies bonded with acrylic tape. Splitting the panel layer without specialized cleanroom environments often damages the liquid crystal layer permanently. Unless you are an experienced electronics technician with dedicated discharge tools, internal repair is generally impractical compared to replacing the unit or having a qualified shop assess it.

Next steps

If basic power resets and cable swaps fail to bring the image back, check if your monitor is still under BenQ's manufacturer warranty. For older out-of-warranty displays facing confirmed panel or driver board failure, compare repair costs against hardware performance by checking our latest hardware reviews to decide if upgrading to a newer panel is the most cost-effective path forward.