I recently upgraded my PC by replacing the CPU, but now it won't display anything on the monitor when I power it on. The power button doesn't seem to work for shutting it down, either. The light on the back of the motherboard is steady, with no flickering, and when I switch back to my old CPU, everything runs fine. I've ensured that my BIOS is up to date and according to the manufacturer's site, my new CPU should be supported. I'm wondering if my new CPU is faulty, or if there might be another issue at play.
Here are my specs:
- Motherboard: Gigabyte B450M DS3H v1, BIOS version: F67 (updated October 28, 2025)
- New CPU: AMD Ryzen 5 5600XT
- Old CPU: AMD Ryzen 5 2600
3 Answers
Have you tried using your old CPU to see if it’s really the new one that's causing the trouble? If your old CPU works fine, ensure you’re connecting the HDMI or DisplayPort to the graphics card and not the motherboard. Sometimes the display output settings can throw a wrench in things. It’s worth confirming your GPU has power too. A dark screen could just mean the GPU isn’t set up correctly.
Definitely try resetting the CMOS as I mentioned earlier. Unplug everything, take that battery out for a bit, and see if that helps at all. As for your worry about the motherboard resetting when changing CPUs, it usually does, so it’s a good idea to double-check your settings after putting the old CPU back. If you reset it, give it a minute before trying to power it on.
First, double-check the CPU installation. Make sure it's seated correctly—they can be finicky! Look for any bent pins too. Also, confirm that the power connections for the GPU are secured. I once forgot to connect mine and faced a similar issue. If all looks good, try resetting the CMOS by unplugging the machine, removing the battery from the motherboard for a few minutes, then putting it back together. That sometimes clears up any BIOS configuration problems that can arise with a new CPU.

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