Second monitor not detected or displaying 'No Signal'
Windows graphics subsystem fails to establish a display handshake with a secondary monitor over or .
Internal desktop parts run on harmless 12V DC voltage and cannot shock you. Simply unplug the wall power cable first, then touch the unpainted metal case frame to ground static electricity.
Common Symptoms & Tells
- Primary monitor works fine, but second display stays black with 'No Signal'
- Settings → Display → Multiple displays → 'Detect other display' reports 'Didn't detect another display'
- Windows Project menu (Win+P) is set to 'Duplicate' or 'Extend' but nothing appears
Interactive Fix Checklist
0 of 4 steps completedRestart graphics driver with hotkey shortcut
Press Windows Key + Ctrl + Shift + B simultaneously. The screen will flicker and emit a short beep as the display driver pipeline restarts.
Ensure both cables connect to the dedicated GPU
Verify both monitor cables are plugged directly into the horizontal graphics card ports on the back of the case, not into the vertical motherboard display outputs.
Verify active input source on the monitor OSD
Use the physical buttons on the second monitor to manually change the input source from Auto to the exact port in use (e.g., ' 1' or ' 2').
Lower refresh rate and resolution temporarily
In Advanced display settings, lower the refresh rate of the primary display or second display to 60Hz to verify that PCIe/cable bandwidth limits are not exceeded.
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