Hi there,
I'm new to the PC building world but have experience with circuit design and custom electronics. I've recently run into an issue after assembly where my build gets stuck in a reboot loop (everything turns on for 3 seconds, shuts-off, turns on for 3 seconds, shuts-off, repeat. etc.) All the enclosure fans revs up too while it is on.
Here are my components:
Enclosure: Corsair Obsidian 250D
Motherboard: ASRock - H370M-ITX/ac Mini ITX LGA1151
CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor
Memory: GeIL - Pristine 16GB (1 x 16GB) DDR4-2400 Memory
Power: EVGA - SuperNOVA G3 750W 80+ Gold Certified Fully-Modular ATX Power Supply
Storage: Samsung - 860 Evo 250GB 2.5" Solid State Drive
Note: I have not selected a graphics card and am hoping to just use the integrated graphics in the core i5.
I had selected these component to ensure they would be compatible. I've just recently confirmed that via PC Part Picker's website.
Timeline of my troubleshooting efforts:
I'm new to the PC building world but have experience with circuit design and custom electronics. I've recently run into an issue after assembly where my build gets stuck in a reboot loop (everything turns on for 3 seconds, shuts-off, turns on for 3 seconds, shuts-off, repeat. etc.) All the enclosure fans revs up too while it is on.
Here are my components:
Enclosure: Corsair Obsidian 250D
Motherboard: ASRock - H370M-ITX/ac Mini ITX LGA1151
CPU: Intel - Core i5-8400 2.8GHz 6-Core Processor
Memory: GeIL - Pristine 16GB (1 x 16GB) DDR4-2400 Memory
Power: EVGA - SuperNOVA G3 750W 80+ Gold Certified Fully-Modular ATX Power Supply
Storage: Samsung - 860 Evo 250GB 2.5" Solid State Drive
Note: I have not selected a graphics card and am hoping to just use the integrated graphics in the core i5.
I had selected these component to ensure they would be compatible. I've just recently confirmed that via PC Part Picker's website.
Timeline of my troubleshooting efforts:
■ After initially installing everything, I decided to remove power from devices that didn't need to be powered in order to isolate the issue.
■ I removed power from SSD. The infinite reboot cycle persisted.
■ I removed all auxillary connectors (USB, audio, etc.). Infinite reboot cycle persisted.
■ I removed power going from the EVGA power supply to the CPU power input (i.e. not the motherboard input). This is the ATX 12V Power Connector (ATX12V1) per the user manual.
Link to motherboard manual - http://asrock.pc.cdn.bitgravity.com/Manual/H370M-ITXac.pdf
■ After removing the CPU power input, the infinite reboot cycle stopped.
■ After plugging the CPU power back in, the infinite reboot cycle came back.
■ Seeing as the problem was directly related to powering the CPU, I assumed there was something incorrect with how the chip was sitting in the socket. I removed the chip and inspected the socket for bent pins etc. It looked okay and re-installed it. However, the infinite reboot problem persisted.
■ So to go more in depth on the infinite reboot problem, when it occurs, the fans (all enclsoure fans and CPU fan) speed up very fast and then the power shuts off. Two things that I could theorize on this: 1) the CPU thinks its very hot. 2) the CPU power is somehow shorting and providing power the fans and giving them a full voltage of something else.
■ So let's assume I'm delivering bad power, I did find the CPU power cable to be rather odd. The EVGO power supply provides a cable that features an 8-pin ATX12V connector on the PSU end, and a 4x2 EPS connector on the motherboard side.
However, the motherboard actually features an 8 ATX12V female connector (i.e. not a 4x2EPS connector). After reading some reviews online, the general consensus is that you can use a 4 pin connector to power the 8 pin socket on the ATX12V. This is essentially what I've been doing.
Illustration:
EVGO (ATX12V 8-pin): (ATX12V 8-pin)------------------------( 4x2 EPS): (ATX12V 8-pin) MotherBoard
This area was the foggiest during the build and is only connection that I've found where I can trigger the infinite reboot cycle. Thus it sticks out. Would there be an issue with me using one of the 4 pin cable connector to the power the 8 pin connector on the motherboard?
■ I have not pulled out a multimeter to check current draw or anything like that yet, however, it seems plausible that my CPU power supply is creating a short circuit and thus faulting the power supply. I've verified that there the motherboard is not shorting against the case, however, I have not attempted to breadboard the system yet.