My computer was running Minecraft last night when my dog lightly bumped the case and the screen immediately froze. I shut the PC down, unplugged it, restarted it, and even removed and reinstalled the graphics card, but the monitor still shows no signal. What else can I safely check before taking it to a repair shop?
3 Answers
The HDMI cable or one of its ports could have been disturbed. Try another cable and test different HDMI or DisplayPort inputs on both the monitor and the computer. If that does not help, a reputable local PC repair shop may be a better option than a large retail service desk.
Try booting with a minimal setup: use only one RAM stick, disconnect the storage drives, and temporarily remove the graphics card if your CPU supports integrated graphics. If it starts, reconnect the parts one at a time to identify the problem component.
Start by reseating the RAM, graphics card, and every internal and external cable. Check both ends of the monitor cable, including the connection at the monitor itself, since the bump may have loosened something. Make sure the cards are firmly seated in their slots.
If your processor has integrated graphics, try connecting the monitor directly to the motherboard video output instead of the graphics card.

Testing one RAM stick at a time fixed mine. One stick worked, so I gradually reinstalled the others and the rest of the hardware until the system was running normally again.