I recently built a PC with a brand-new Gigabyte B550 Gaming X V2 (Rev. 1.3) motherboard and a Ryzen 7 4750G. When I press the power button, the CPU and case fans spin and the RAM lighting comes on, but there is no display and I cannot enter the BIOS. The system appears to power-cycle once or twice during startup before remaining powered on, and the motherboard's diagnostic LEDs have not behaved consistently. I have confirmed that the 24-pin motherboard cable, 8-pin CPU cable, and CPU fan are connected. I have also reseated the RAM and tried different slots. The 4750G was previously used in another computer where RAM was removed while the system was running, which damaged the RAM slots, so I'm unsure whether the CPU could also have been affected. Could this be a BIOS compatibility issue, defective CPU, RAM problem, or something else? What should I test first to narrow down whether the motherboard or processor is at fault?
2 Answers
Try to eliminate the simple display and memory issues before assuming the CPU is dead. Test with one RAM stick in the recommended slot, clear the CMOS, and try another monitor cable or display. Also make sure the cable is connected to the motherboard’s video output, since the 4750G has integrated graphics. A monitor briefly detecting a signal does not necessarily mean the system is completing POST.
The first thing I’d check is the BIOS version. A new board may have been sitting in storage for a while, and the Ryzen 7 4750G may require a newer firmware version than what was originally installed. This board supports Q-Flash Plus, so you should be able to update the BIOS using the dedicated flash process, even if the system does not currently reach the BIOS. Follow Gigabyte’s instructions carefully and use the correctly named BIOS file.
I’ll try updating the BIOS first. I’m still wondering whether the CPU could have been damaged when the RAM was removed while the old system was powered on.
I’ll test another cable and run the system with a single memory stick. The monitor does flash as if it detects something when I connect it, but there is still no usable image.