My PC had been working normally for over a year while I was watching YouTube, then it suddenly froze completely. The mouse stopped moving, keyboard shortcuts did nothing, and even the power button would not respond, so I switched off the power. After restarting, the system no longer reaches POST and the monitor stays completely black. The motherboard's red CPU diagnostic light remains on, although all fans spin and the RGB lighting works. I tried booting with each RAM stick individually and flashed the latest BIOS, but there was no change. I have not recently moved or modified any components. The system uses an ASRock B850 Steel Legend motherboard, AMD Ryzen 5 7600X, Radeon 9070 XT, 32 GB Patriot Viper DDR5, and a be quiet! 750 W power supply. What else should I check, and could the CPU or motherboard have failed?
2 Answers
The motherboard could also be the problem, especially if the CPU diagnostic light stays on after reseating and clearing the basics. After a BIOS flash, the first boot can take several minutes while the board retrains the DDR5 memory, so leave it powered on for a while before interrupting it. If there is still no display afterward, try clearing CMOS, booting with only the CPU, one RAM stick, and the graphics card, and verify both the 24-pin motherboard cable and 8-pin CPU power cable. Testing with another CPU or motherboard is the most reliable way to isolate the failed part.
Reseat the CPU and inspect the socket carefully for bent or damaged contacts. Also check that the CPU power connector is fully seated. If the system still shows the CPU light, testing with another compatible AM5 processor would help identify whether the CPU or motherboard is at fault. Since the 7600X has been working for a year, a sudden CPU failure is uncommon, but it is still possible and warranty replacement may be the next step.
I reseated the CPU and the socket contacts look fine, but the problem is unchanged. I can return the 7600X, although I was surprised that a CPU could fail so suddenly.
The monitor has no signal at all and remains completely black. I will give the system time after the BIOS update, then try clearing CMOS and checking the power connections.