[SOLVED] No POST on power on.

[cacause1]

PC Specs:
CPU: Intel Core i5-8600K Coffee Lake 6-Core 3.6 GHz (4.3 GHz Turbo) LGA 1151 (300 Series) 95W BX80684I58600K Desktop
Motherboard: MSI Z370I GAMING PRO CARBON AC LGA 1151 (300 Series)
GPU: EVGA GeForce GTX 1060 6GB FTW+ GAMING ACX 3.0
Storage: Samsung 960 Evo M.2 NvMe
Memory: CORSAIR Vengeance LPX 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3000
PSU: EVGA 550 B3, 80 Plus BRONZE 550W, Fully Modular, EVGA ECO Mode, Compact 150mm Size, Power Supply 220-B3-0550-V1
Case: NZXT H200i

Before asking this question I went through the no post guide posted on this form and didn't find a solution. https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/

Problem:
On Saturday night I left my computer online and woke up on Sunday to it powered off. I assumed there was some kind of brief power outage and my PC powered off. On pressing the power button, there was no system fans, LED, CPU or GPU fan spin, no monitor display (they didn't even register a computer was connected). The only thing that happens is when I flip the PSU switch from off to on, I get a single red LED blink from the motherboard corresponding to "indicates CPU is not detected or fail" (according to mobo manual). If it's not the first time the power button has been hit since the PSU was switched to on, there is no LED blink and the computer still does nothing. I built this PC myself in 2018 and it has run extremely well ever since. This is the first time I've ever had this system fail to boot, let alone POST. I've tried using one stick of RAM, unplugging GPU, the motherboard is on their proper stands, nothing is making it short out, I've reseated the PSU cables to the motherboard.

My current idea as to what happened:
This is looking like a component failure to me. I think my RAM, GPU, SSD is fine. I did have the BIOS setting "Game Boost" or something like that which had my CPU running at 4.3Ghz. I don't think this would be alone to kill my CPU after 3 years since I've only done gaming (usually not AAA or too hardware intensive so I'm not maxing out the CPU usage) and relatively small coding projects. I think this may be either a CPU, PSU or motherboard failure. I've looked at each 3 and did not see any "obvious" reasons to why they wouldn't work (no physical damage or blown out capacitors). The last time I can remember seeing my thermals, my CPU was at ~50C and my GPU ~45C on the desktop with some Chrome tabs open. I'm pretty broke as I'm a college student, so I'm really hesitant to order a replacement part without being pretty certain of which component has failed.

Edit: I also forgot to mention I have already tried clearing the CMOS via the button on the motherboard.

If I have left out any information you would need to help me find a solution, please ask and I will happily provide it.

 

[Blackink]

PC Specs:
CPU: Intel Core i5-8600K Coffee Lake 6-Core 3.6 GHz (4.3 GHz Turbo) LGA 1151 (300 Series) 95W BX80684I58600K Desktop
Motherboard: MSI Z370I GAMING PRO CARBON AC LGA 1151 (300 Series)
GPU: EVGA GeForce GTX 1060 6GB FTW+ GAMING ACX 3.0
Storage: Samsung 960 Evo M.2 NvMe
Memory: CORSAIR Vengeance LPX 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3000
PSU: EVGA 550 B3, 80 Plus BRONZE 550W, Fully Modular, EVGA ECO Mode, Compact 150mm Size, Power Supply 220-B3-0550-V1
Case: NZXT H200i

Before asking this question I went through the no post guide posted on this form and didn't find a solution. https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/

Problem:
On Saturday night I left my computer online and woke up on Sunday to it powered off. I assumed there was some kind of brief power outage and my PC powered off. On pressing the power button, there was no system fans, LED, CPU or GPU fan spin, no monitor display (they didn't even register a computer was connected). The only thing that happens is when I flip the PSU switch from off to on, I get a single red LED blink from the motherboard corresponding to "indicates CPU is not detected or fail" (according to mobo manual). If it's not the first time the power button has been hit since the PSU was switched to on, there is no LED blink and the computer still does nothing. I built this PC myself in 2018 and it has run extremely well ever since. This is the first time I've ever had this system fail to boot, let alone POST. I've tried using one stick of RAM, unplugging GPU, the motherboard is on their proper stands, nothing is making it short out, I've reseated the PSU cables to the motherboard.

My current idea as to what happened:
This is looking like a component failure to me. I think my RAM, GPU, SSD is fine. I did have the BIOS setting "Game Boost" or something like that which had my CPU running at 4.3Ghz. I don't think this would be alone to kill my CPU after 3 years since I've only done gaming (usually not AAA or too hardware intensive so I'm not maxing out the CPU usage) and relatively small coding projects. I think this may be either a CPU, PSU or motherboard failure. I've looked at each 3 and did not see any "obvious" reasons to why they wouldn't work (no physical damage or blown out capacitors). The last time I can remember seeing my thermals, my CPU was at ~50C and my GPU ~45C on the desktop with some Chrome tabs open. I'm pretty broke as I'm a college student, so I'm really hesitant to order a replacement part without being pretty certain of which component has failed.

Edit: I also forgot to mention I have already tried clearing the CMOS via the button on the motherboard.

If I have left out any information you would need to help me find a solution, please ask and I will happily provide it.

Sounds exactly what my home built PC did a few months ago and it was the power supply. Mine was just over 5 years old and the warranty was only good for 5 years-good timing there!!

The PC was running fine one day and the next morning it was off. It wouldn't start up, I opened the case and removed the CMOS battery but that did nothing. I was seeing a red light on the mobo so I didn't think it was the PSU. I didn't have a spare power supply to test it with so I brought the computer to a local repair shop and 30 minutes after dropping it off, they confirmed it was the power supply.
The cost for the test was $25. Cheap enough and I then purchased a Seasonic PSU with a 10 year warranty.

I can't say a new PSU will solve your problem but the symptoms are very similar.

 

[cacause1]

Sounds exactly what my home built PC did a few months ago and it was the power supply. Mine was just over 5 years old and the warranty was only good for 5 years-good timing there!!

The PC was running fine one day and the next morning it was off. It wouldn't start up, I opened the case and removed the CMOS battery but that did nothing. I was seeing a red light on the mobo so I didn't think it was the PSU. I didn't have a spare power supply to test it with so I brought the computer to a local repair shop and 30 minutes after dropping it off, they confirmed it was the power supply.
The cost for the test was $25. Cheap enough and I then purchased a Seasonic PSU with a 10 year warranty.

I can't say a new PSU will solve your problem but the symptoms are very similar.

Would the CPU red LED on the motherboard blink with a dead PSU? I'm thinking maybe the PSU is outputting a little power, but not enough to initialize the CPU in the POST?

 

[Blackink]

I can't answer your first question but I know my power supply was putting out enough power to make a red LED light up, maybe 2 of them but I can't remember which ones. I'm pretty sure one of the lights was telling me I had power on, but obviously it wasn't enough power to fire up the computer with the attached hardware.

 

[ying0410]

Look for the post that teach you how to short the PSU fan to test if it's working. Or you can get a testing kit for $15 on Amazon to do it safer, since it's kind hard to get tech support's help nowadays.
It's rare that a PSU went completely dead overnight, but the symptoms does indicate a bad PSU since you cant even get the fan on.