I bought a brand-new Armoury Phantom prebuilt PC and an LG UltraGear monitor yesterday. Everything worked normally during setup, but after choosing Windows 11's "Update and shut down" option, the monitor now shows no signal. I've already unplugged and reconnected the cables, but I have very little computer experience. The keyboard's Caps Lock and Num Lock lights also don't respond when I press them. What can I safely try before taking the PC back for diagnostics or warranty service?
3 Answers
You can also test the monitor and cable separately if possible: try the LG monitor with another device, or try another known-working monitor or cable with the PC. If the monitor works elsewhere but the new PC still produces no signal, the graphics card may have shifted or failed, or the system may have a startup fault. Because the machine is brand new, opening it up or removing components could affect warranty coverage, so returning it to the retailer is the safest next step if the basic cable and power checks fail.
Since the Caps Lock and Num Lock indicators aren’t toggling, the computer may not be completing its startup process. That makes it unlikely that you can fix this through Device Manager or by reinstalling graphics drivers, because Windows may not be loading at all. Check that the PC’s power switch is on and that its fans or status lights activate. If you get no BIOS logo on any monitor input, contact the seller for a replacement or diagnostic service instead of changing BIOS settings.
Start by completely powering everything down. Unplug the PC and monitor from the wall, disconnect and reconnect the HDMI or DisplayPort cable at both ends, wait about 10 seconds, then power on the monitor first and the PC second. Make sure the display cable is connected to the graphics card ports rather than the motherboard video ports. If the PC has multiple HDMI or DisplayPort sockets, try another one. You should normally see the manufacturer logo or BIOS screen before Windows loads; if there’s still no image and the keyboard lights don’t react, it may be a hardware or startup problem rather than a Windows driver issue.
I’ll try the other ports and a full power reset. If nothing changes, I’ll probably return it under warranty.