The PC isn't turning on, and all components are inactive. Could your CPU be faulty?
The PC isn't turning on, and all components are inactive. Could your CPU be faulty?
Hello everyone, I hope you're all doing well. This problem I'm dealing with is quite urgent, and I'm being honest about it—no time to waste. I have my exams coming up in a few days, and about two weeks ago, before diving into online revision sessions, I decided to disassemble my PC and swap out the case, fans, and GPU. I bought these new components and was really excited, but then the PC wouldn't even start. I tried various fixes I found online—removed some RAM sticks, adjusted the CMOS for a short time—but nothing worked. Initially, the motherboard lights would come on, but soon they stopped working altogether. Eventually, I gave up and handed over the PC to a technician who diagnosed it as having issues with the motherboard and power supply unit. He replaced the PSU, motherboard, and even upgraded everything else except the CPU and GPU, which were new. Still, after hours of attempts, nothing happened. The motherboard lights don’t light up at all, and the fans are completely unresponsive. I’m really in need of help now, as I’m nearing the end of my revision period and need to access certain folders. My main concern is figuring out what’s wrong—based on what I can see, nothing seems faulty with the GPU (it's a brand new 3090), but the CPU appears to be the culprit. I noticed several bent pins that needed straightening, and sometimes when I take off the CPU cooler, it sticks to the board even though it shouldn’t. My PC parts include a Gigabyte RTX 3090, a 9GB 5950x, a B550 VISION D-P DDR4, Corsair Vengeance 8GB x4, an ADATA XPG SX8200 PCIe drive, and a Lian Li O11 dynamic case. I’m planning to remove everything now so I can reassemble it properly. Please help me understand what’s going on.
It seems the CPU is likely the only component still needing attention, though there are other considerations. Certain B550 models need a BIOS upgrade for Zen3 compatibility. Others support USB updates, while some depend on a working processor that matches the existing BIOS version.
Thanks for the update, it's good to hear you got the motherboard from AWD-IT with a Ryzen 5000. I’m wondering if a faulty CPU would affect the fans and RGB lighting too. If that’s possible, I’d strongly suspect the CPU is the problem. Otherwise, I’m not sure.
It relies on how your fans are managed. Some fan units run separately from the SATA, skipping the CPU and motherboard. However, if they depend on the motherboard or the controller needs it, a problem could disable them entirely. Are you in Virginia by chance? I have an idle machine with a B450M and 1700 Ryzen that I could possibly lend you while you fix this. If not, consider installing an affordable AM4 board for testing now. Edited June 4, 2022 by An0maly_76 Updated, more info
You're very welcome, dear friend. It's really nice of you to offer your help. I understand the situation well—being from the UK makes it impossible for me. The fans on the motherboard are connected to the motherboard itself, which explains why they aren't working. Regarding the fans and lights, they should still operate if the CPU is damaged. It's frustrating, but your quick response means I'm hopeful we'll get a solution soon. Thank you so much for your support and kindness.
I’d begin testing each part individually... Remove all components from the case, check instructions for starting a PSU without a mainboard—you’ll need a way to verify it’s active, such as a multimeter for voltage checks or a SATA-powered fan hub. If the PSU fan starts, that’s useful, but I suspect it won’t spin until it reaches a certain temperature without load. Once confirmed, connect the mainboard without any CPU, RAM, SSD, GPU, or other parts, and see if it can power up (including fans or LEDs). Then add the CPU, RAM, SSD, and GPU one at a time, observing whether performance improves or stops.
Mobos include diagnostic indicators, typically positioned close to the ATX port — covering CPU, RAM, VGA, and boot settings. When a problem arises, they change color, often white or red depending on the board. Should a power fault occur, the board will not receive power to address it.
This guide offers a solid way to test your PSU by jumping it out. Make sure you connect to the right ground on the correct connector during voltage checks. Keep in mind that certain PSUs need a light load—something as simple as a hard drive can help initiate the process.
I’d verify that your power source is active and that the connection on your case’s power port matches the instructions. Also, ensure all 24-pin ATX and CPU 8-pin power connections are secure, just like confirming every cable is firmly attached.
So my friend brought over his brother with an RM750, but it won't fit in the case. I'm going to test this PSU just to be sure. I think I might have mixed up the cables for the GPU—maybe I'm adding the wrong ones. I've seen others use two PCIe cables for the 3090, and some use one. Here are some images to clarify.