I'm building a new PC with a Ryzen 5 5600, MSI B550M PRO-VDH WIFI motherboard, ASUS RX 7600 8GB graphics card, MSI MAG A650BN 650W power supply, and 16GB Kingston HyperX Fury DDR4-3200 memory. The motherboard's CPU debug LED stays lit and there is no display. I've removed and reseated the CPU, cleaned and reapplied the thermal paste, removed and reinstalled the CMOS battery, and tried different RAM sticks. The monitor is connected to the graphics card, and all of the parts are new. What else should I check, and how can I determine whether the CPU or motherboard is faulty?
2 Answers
Make sure the display cable is connected to the RX 7600 rather than the motherboard’s video outputs, since the Ryzen 5 5600 does not have integrated graphics. Also reseat the graphics card and its PCIe power cable, install one RAM stick in the recommended slot—usually A2—and clear CMOS properly with the power supply switched off. Check that the motherboard’s 24-pin and CPU EPS power cables are both connected. If the CPU debug light still stays on after a BIOS update and these checks, the motherboard or CPU may need to be replaced or tested in another system.
First, confirm that the motherboard has a BIOS version supporting the Ryzen 5 5600. Some B550 boards were shipped with older BIOS versions. Use the board’s BIOS Flashback feature with the latest BIOS from MSI, following the manual’s instructions exactly. If the CPU light remains on afterward, check that the 8-pin CPU power connector is firmly attached, reseat the processor, and inspect the socket for bent or damaged pins. If possible, testing with another compatible CPU or motherboard will identify which part is defective.
The parts are all new, and the monitor is connected to the graphics card. I’ll try updating the BIOS with Flash BIOS and then recheck the CPU power connection and socket.