Hey there! I'm not new to building PCs, but I've run into a pretty confusing issue this time. I recently upgraded my motherboard, CPU, and RAM but decided to reuse my PSU and GPU to save some cash. After assembling everything, I gave it a go and the system powered on once—lights, fans, and a couple of little status LEDs lit up. However, when I tried to power it up again, nothing happened.
I've checked that the GPU is seated correctly, verified all connections, and even tried swapping around the RAM but no luck. I've tested with just one stick of RAM, tried different slots, and even different PCIe ports for the GPU. I also removed the GPU entirely, but still, nothing happens. I'm starting to worry that I may have fried my PSU or something worse.
Before proceeding with this build, I did use a compatibility checker and it mentioned a warning about my PSU lacking an 8-pin power connector that provides extra power, although it noted that the system should still work without it. Here's what I'm working with:
- Ryzen 5 9600x
- Asus TUF B850 Plus Wi-Fi
- 32GB Crucial Pro DDR5 RAM
- 2 Samsung 990 NVMe SSDs
- RTX 2070 Super
- EVGA 700 BR 700W 80+ Bronze PSU
2 Answers
To see if your PSU is still working, you can check it by shorting the green wire on the 24-pin connector to any of the black ground wires. That should power it up, assuming it's still functional. Once you've done that, turn it off and reattach the connector to the motherboard. Try removing the front panel header and shorting the power switch terminals to test if the board will power on directly.
Have you tried resetting the CMOS battery? Sometimes a simple reset can fix power issues.

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