I built a new PC with a Ryzen 7 7800X3D, MSI PRO B650-S WiFi motherboard, Gigabyte Radeon RX 9070 XT, and 32GB of Corsair Vengeance RGB DDR5-6000 RAM. One of the original memory modules was faulty, but the replacement kit now works normally once Windows loads. The problem is that the computer sits on a black screen for more than 10 minutes before booting. There are no warning lights showing on the motherboard, and after startup the system runs reliably, including during several hours of gaming. The system drive is a 1TB WD Black SN850X NVMe SSD, powered by a Corsair RM850e in a Lian Li LANCOOL 217 Infinity case. What could be causing the extremely long startup?
3 Answers
Power the system down, reseat both memory sticks, and install them in the motherboard's recommended slots, usually A2 and B2. Then clear the CMOS and try booting with EXPO disabled. If startup becomes normal, enable EXPO again and test it. If the delay returns, run the RAM at default settings or adjust the memory speed and firmware rather than leaving it to retrain every boot.
This sounds like DDR5 memory training, which is fairly common on AM5 systems after changing RAM or enabling EXPO. Check the BIOS for Memory Context Restore and enable it after confirming the memory is stable. Also make sure the BIOS is up to date and that EXPO settings are not too aggressive. Ten minutes is still far longer than normal, though, so the board may be repeatedly failing and retrying memory training.
Since this is a fresh build, clearing the CMOS and updating or reflashing the motherboard BIOS would be reasonable. Start with only the necessary hardware connected, confirm the SSD is detected, and test one memory stick at a time if needed. The SSD, case, and 850W power supply are unlikely to explain a long black screen before POST, especially since the PC is stable once it finally starts.
Memory Context Restore should prevent a full training cycle on every startup, but it is best to verify that the EXPO profile is stable first. If the machine still takes several minutes at stock settings, check for a BIOS update or a memory or motherboard fault.