PC sometimes does not boot until internal wires are wiggled

kamsahn

Hello,

I've recently built my PC (mid-November) with some pieces from MC. It has been working smoothly until a week or so ago when I went to turn it on and the computer did not boot. Specifically these things happened: the case power LED turned on, my RGB memory lights up, and (via feel and faint sound) the psu fan is running. These things are not happening: the case fans are not spinning, the cpu cooler is not spinning, monitor detects no signal from HDMI cord hooked up to the GPU. When this happens, I cannot turn the computer off by pressing the power button, even if I hold it down for 10+ seconds as if trying a hard-reset. I have to switch the PSU off. I will then unplug the PSU power cable, HDMI cable, ethernet cable and keyboard usb connectors from the back and open up the pc. I don't see any dust or obvious disconnections. I wiggle all the connections on the motherboard and the wiring from my case and then it starts to work again. I will close the case back up and it will turn on and off normally for a few cycles and then the problem will arise again.

I mainly suspect the 24-pin connector since its at a pretty sharp angle (coming out from the back of the case and bent 180 degrees to plug into the motherboard), but I wiggle most connections as described above. Next time the problem arrises, I will isolate the 24 pin connector to confirm/deny my suspicions. 

I have tried just flipping the power switch off, waiting 5+ min, and switching it back on, but that did not fix the issue. I only got as far as the case LED and RGB ram lighting up, but no fans or boot. 

Maybe a related note: on one successful run, I opened up bios and noticed some custom configurations were no longer present. I set them sometime in November when the pc was running smoothly. I have since reset my custom configurations and saved+restarted and I can still see the changes persisting as desired. 

My part list is as follows:
CPU: Ryzen 5 3600 (from MC) + stock cooler
Motherboard: ASRock B450M Pro4 AMD AM4 mATX (from MC)
PSU: PowerSpec 550W 80+ Bronze Certified Non-Modular (from MC)
Case: Lian Li 205M (from MC)
Memory: Corsair Vengeance RGB Pro (2 x 8 GB) DDR4-3000 CL16 Memory
GPU: MSI Gaming MX 5600XT
Storage: Western Digital 500GB WD Blue NVMe SSD


I would like to try to solve this within the extended return period (Jan. 15) in case I need to return / exchange parts. Thank you in advance!

PowerSpec_MikeW

Greetings @kamsahn

Being unable to shutdown the system by holding the power button, tells you the motherboard becomes unresponsive.  Since the fans don't spin, it must be happening almost immediately. Nothing here besides working the problem by process of elimination. Wiggle the cables one at a time to isolate it, or test another power supply altogether.