PC refuses to start, CPU indicator illuminated, (short-term solution identified)
PC refuses to start, CPU indicator illuminated, (short-term solution identified)
The PC won't boot after shutdown, even though it seems ready to start. The fans are running at full speed, causing the CPU light to appear. It doesn’t progress past BIOS and then the operating system. The only workaround I discovered is turning off the display port on the GPU, which turns off the light, and then reconnecting it—this restores functionality without the fans spinning too fast. After this temporary fix, I suspected the issue was related to the GPU, so I tested three different GPUs, but the same problem persisted. CPU performance is normal, and a 12-hour stress test was completed. I’m unsure why it activates under these conditions or if there’s a recurring pattern.
It seems like a motherboard problem might be the cause, so I could recommend removing the graphics card entirely and testing the HDMI output from the board to determine if the issue persists. There could be a problem with the PCIe circuit on your board. Given that three different graphics cards produce identical results, it likely points to the board itself, though something unusual might still be at play.
Using the HDMI output without any graphics card installed should provide some insights into what we don’t yet understand. The presence of a CPU light instead of a GPU light hints that possibly a motherboard pin that was slightly bent during installation may have deteriorated over time, leading to the current issue. It might be wise to remove the CPU cooler and CPU, inspect the board closely with a magnifying glass for any bent pins, and replace the thermal paste afterward—cleaning both the CPU heatspreader and the bottom of the cooler as needed.
Additionally, consider disconnecting all other hardware, such as drives, third-party fans or RGB controllers, except one memory stick, to see if the problem remains with minimal components attached.
Trying it on the second slot is definitely an option, and that too will tell us a few things.
It CAN tell us whether there is a problem with ONLY that specific slot if it works fine in one of the secondary slots BUT keep in mind that for MOST boards, the secondary or tertiary PCIe slots usually won't run at the full x16 speed that the primary slot runs at. Some will, but most of them usually won't. Usually the secondary slots will only run at x8 speeds even if there is not already a card installed in the primary x16 slot. But for the purposes of troubleshooting, it's fine as a tool.
It might also tell something if neither slot wants to work properly, but then again, it might not tell us anything other than the problem still exists rather than it's specifically a problem with the PCIe bus somewhere.
Always good to have an HDMI cable on hand, and to be honest if you have a repair shop anywhere near you and if they are anything like I am with my services, they might be willing to just let you borrow one as they likely have dozens of them, because it's good customer service that might bring in a new customer if the cable doesn't help to identify the problem. Of course, you can just take it back to them and not take them your business if you choose to or if you find the problem on your own. Personally I think it's just better to have one on hand because sometimes problems simply develop with a specific port on a graphics card while using a different port or different type of port works fine. And for other things like connecting additional monitors to your system or a laptop or whatever. I too have dozens of them but then again I work on systems as a semi-profession anyhow.