I unplugged my graphics card and gently brushed dust from its fans with a toothbrush while holding it face-down. I also removed the front panel to clean the front intake fan. After reinstalling the graphics card, the computer powers on but the monitor reports no HDMI signal. The graphics card still lights up, the fans spin, and the monitor's light bar is on, but the keyboard's Caps Lock indicator does not respond. I have already cleared the CMOS, reseated the graphics card and RAM several times, unplugged the power supply and held the power button for 30 seconds, and checked the rear cables. I do not have integrated graphics or a spare graphics card to test. What should I try next?
3 Answers
The lack of a Caps Lock response suggests the system is not completing POST, so the missing HDMI signal is probably only a symptom. Start with the RAM: remove every stick, inspect the slots, then install one stick firmly in the motherboard’s recommended slot. Make sure both retention clips fully lock. After that, reseat the graphics card and check that its PCIe power connector is completely inserted at both ends. The lights on the card only confirm that it is receiving some power, not that the system has booted.
If the motherboard has diagnostic LEDs or a speaker, check whether it reports a RAM, CPU, or graphics error. Also inspect the graphics card slot and the board for dust or anything that may have shifted. Avoid using a vacuum directly on the components, and make sure the system is fully disconnected from power while reseating parts. If it still fails with one known-good RAM stick and the minimum hardware connected, the next useful test would be another power supply, graphics card, or motherboard.
Since reseating everything has not helped, disconnect the PC from wall power and reduce it to the minimum setup: motherboard, CPU and cooler, one RAM stick, graphics card, and the power connections required for those parts. Disconnect storage drives, USB devices, and front-panel accessories temporarily. Check that the 24-pin motherboard connector, CPU power connector near the processor, and GPU power cable are firmly seated. Then try booting with each RAM stick individually and in the recommended slot.
The power supply itself was not opened or disturbed, but I did unplug the main AC cable while moving the computer. I’ll double-check the motherboard and CPU power connectors as well.
The case fans spin normally. I’ll try testing the RAM one stick at a time and reseat the graphics card again.