Dan built a computer using an AMD Ryzen processor. He's been watching YouTube videos a lot on doing it and is ready to give it a go. Leo says there's a lot of great information on YouTube, but sometimes they can get it wrong, so keep that in mind. It worked for five days and then just stopped working. Leo says that building a computer is a great project, but if something like that goes wrong, you are your own support. There's no one really to call, as everyone will blame the other guy for the problem. So you end up having to go one by one to determine what goes wrong.
Josh built his own computer, but when he turns it on, sometimes it stalls on the POST (Power On Self Test). Leo says that it could be a cold solder connection, which needs to heat up a bit before the connection is made and the motherboard boots up. But that is rare these days. It could also be a flakey power supply. Another thing to check is if the RAM is properly seated.
Leo thinks the most likely cause is that the BIOS is corrupt. He should try and refresh it. If that doesn't work, he can try and reinstall the BIOS firmware. It could also be physically damaged, though.
Dale is having issues with his old Mac Pro tower. He got a new Ben Q monitor and he has an intermittent problem where the boot up takes a long time before getting to the login page. Leo says that when you power up a computer, it has what's called a Power On Self Test (POST). Leo says it could be a monitor thing. A faulty cable or loose connection could cause it. Sometimes a USB device can hold you up. So try unplugging all your USB devices and see if it makes it faster. If so, then you have a flakey USB cable or device.
Brad built a computer running Windows and now it just shuts down while he's still using it. Leo says it sounds like a bad power supply. Brad replaced it, though. Leo says that's the downside of building his own machine -- he'll have to hunt down the problem himself. Leo suspects that since the power supply didn't fix it, the motherboard is probably the culprit. It could have been from a power surge. He should try replacing the battery for the BIOS and see if that resets it. If that doesn't work, it could be the motherboard. The next thing to address would be the CPU.