The ROG Crosshair VIII Dark Hero Motherboard features advanced connectivity for seamless gaming and high-performance networking, it offers proper support for AMD Ryzen processors and it can take up to 128GB of DDR4 RAM. It was specifically crafted for the most advanced computers and it can be a must-have for passionate gamers, but despite its considerate price, many users have been reporting a rather troublesome defect that is forcing them to open different RMA tickets, either for repairs or a full refund. The issue in question is related to the power button not booting the system after shutdown, hibernate or sleep, unless the PSU switch is reset.
There might be different reasons affecting the power button on your computer case. If nothing happens when you press it and the PC stays off, it could be that your PSU is faulty, or there might be some loose screws and/or cables somewhere (either on the Motherboard or power button itself). You may also fix similar problems by updating your BIOS, but with the Dark Hero the matter seems to be a different story.
The Motherboard’s LEDs stay on after shutdown, along with the Start button on it lit in white. This sorta works like a low power mode where some external devices remain active and the USB ports can be used to recharge your phone or other tools. However, the moment you try to boot the system up with the power button the following day, in most cases nothing happens and you are forced to cut off the power from the PSU with the back switch and reset it. This will send the proper input to the Motherboard and the power button will start working again, only for one boot or more before failing again.
Now, if your computer is stable and does not present any visible problem, it may not be a big deal in terms of functionality. Still, from such an expensive component you would definitely expect more and this issue is simply not acceptable. If you have already tried fixing the connection of the power button, no screws or cables appear to be loose and you are certain the PSU/any other component is perfectly healthy, then it is 100% the Dark Hero glitching out.
Unfortunately, people on the ASUS Forum have reported that even the repaired version presents the same hiccup and, despite waiting for their RMA ticket to be resolved, they are back on square one. What’s causing this startup problem on such a big batch is most likely still unknown, someone has mentioned the possibility of the Motherboard’s Chipset being faulty, but ASUS didn’t publicly address this yet and it’s been discussed by customers for months. All in all, the system might work smoothly and run fine without a single crash or reboot, but having to reset the PSU every day or so to turn it on is quite absurd.
If you do not use the WOL (WakeOnLan) option, you aren’t interested in turning the system on with the mouse or keyboard and never really use the USB ports to recharge your devices at night, a good solution is the ErP feature in BIOS. The ErP (S4+S5)‘s location might differ depending on your BIOS version and overall setup, it could be under Settings/Advanced > ACPI Configuration, Platform Power, or Advanced APM and it essentially turns everything off after shutdown just like older computers do. The Dark Hero somehow fails to power up the system if its default mode is active and ErP is off, but it works fine if this setting is enabled.
However, if your computer still fails to turn on with the power button using ErP, then it could be truly related to faulty hardware or anything that cannot be resolved in BIOS alone. A good way to test it would be with a temporary motherboard, should you have one at your disposal.