help enabled EXPO and got a black screen for minutes on first boot

Question

put my trident z5 kit on a fresh am5 board this week, flashed the latest bios, enabled EXPO and hit the power button. black screen. motherboard debug code just sitting there for what felt like forever, a few minutes at least. had my hand on the power button ready to force it off.

it did eventually boot and its been fine since, but now i'm paranoid. same kit ran perfect on the old board. is this normal for a new kit or is something on the way out. anyone seen a black screen hang this long after enabling EXPO

calibration_guy · Accepted Answer

That was memory training. On POST the board tests signal margins across your timings and voltages, and 10 to 45 seconds is typical on a mature BIOS, while several minutes is normal right after a flash or with a kit it has never seen. The debug code you saw is the standard AM5 training stage. Just let the first boot finish. Powering off mid-training is what causes the instability people are trying to avoid.

rgbwhenever · Answer

had the exact same black screen last year and literally had the box out ready to RMA before someone explained training. now i make a coffee on first boot after a bios update and let it do its thing

fanspinning · Answer

black screen on boot is the scariest part of building lol