I assembled a PC from second-hand parts, but when I power it on, the fans spin and the components light up while the CPU and DRAM diagnostic LEDs remain lit. The system repeatedly restarts without reaching the BIOS.
The build uses an ASRock X570 Steel Legend motherboard, AMD Ryzen 5 5500X3D with a Wraith Prism cooler, Samsung DDR4-2933 memory, a SilverStone DA850 Gold power supply, an ASUS Radeon RX 6750 XT, two SSDs, and a be quiet! Silent Base 802 case. The SSDs and RAM were previously used in another working system, so I believe those parts are functional.
The components appear compatible on paper, but I'm not sure how to isolate the cause of the boot loop. What troubleshooting steps should I try first?
3 Answers
This sounds like a failed POST and boot loop rather than a completely dead motherboard. Start by powering down, disconnecting the PSU, and clearing the CMOS. Then try booting with only the CPU, cooler, one RAM stick, and the graphics card installed.
Reseat the memory and verify the slot arrangement in the motherboard manual. For a single DIMM, the recommended slot is commonly the second slot from the CPU, but confirm the exact location for this board. Also clear the CMOS before testing again, disable XMP or DOCP, and try each memory module by itself if you have more than one.
I checked the manual, and the second slot is the recommended one for a single stick. That’s where I installed the RAM.
Check the motherboard BIOS version carefully. Older X570 boards originally supported Ryzen 3000 processors, while the 5500X3D may require a much newer BIOS. If the board cannot recognize that CPU, the CPU and DRAM lights can remain on and the system may keep restarting. If possible, install a known-compatible processor, update the BIOS, and then reinstall the 5500X3D.
I may try my Ryzen 5 3600XT from the working computer. If the system starts with that CPU, I should be able to update the BIOS.
If it’s a boot loop, should clearing the CMOS be the first thing I try?