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PC refuse to start with the 12v CPU line connected

DoctorJohnSmith
By DoctorJohnSmith
in Troubleshooting
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Hi, recently my pc is having trouble turning on after idling for a good 8-9 hours. Whenever i tried turning it on the fans spins for a brief seconds and stops, i tried to disassemble and reassemble the pc but nothing works. I also tried changing the CMOS battery in a desperate attempt and it also didn't work. However, when i forgot to plug the 12V cpu line the computer starts, with all fans spins 100% all the time with no video output.  The problem comes back when i reconnect the 12V power.

 

I'm guessing a bad PSU or a bad motherboard but i need a second opinion on this.

 

Thank you for your time

 

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6 minutes ago, AmazingRez97 said:

However, when i forgot to plug the 12V cpu line the computer starts, with all fans spins 100% all the time with no video output. 

In that case you're not powering your CPU, which means the board runs as if it doesn't have one installed. Your CPU seems to be the problem then.

CPU: i7-2600K 4751MHz 1.44V (software) --> 1.47V at the back of the socket Motherboard: Asrock Z77 Extreme4 (BCLK: 103.3MHz) CPU Cooler: Noctua NH-D15 RAM: Adata XPG 2x8GB DDR3 (XMP: 2133MHz 10-11-11-30 CR2, custom: 2203MHz 10-11-10-26 CR1 tRFC:230 tREFI:14000) GPU: Asus GTX 1070 Dual (Super Jetstream vbios, +70(2025-2088MHz)/+400(8.8Gbps)) SSD: Samsung 840 Pro 256GB (main boot drive), Transcend SSD370 128GB PSU: Seasonic X-660 80+ Gold Case: Antec P110 Silent, 5 intakes 1 exhaust Monitor: AOC G2460PF 1080p 144Hz (150Hz max w/ DP, 121Hz max w/ HDMI) TN panel Keyboard: Logitech G610 Orion (Cherry MX Blue) with SteelSeries Apex M260 keycaps Mouse: BenQ Zowie FK1

 

Model: HP Omen 17 17-an110ca CPU: i7-8750H (0.125V core & cache, 50mV SA undervolt) GPU: GTX 1060 6GB Mobile (+80/+450, 1650MHz~1750MHz 0.78V~0.85V) RAM: 8+8GB DDR4-2400 18-17-17-39 2T Storage: HP EX920 1TB PCIe x4 M.2 SSD + Crucial MX500 1TB 2.5" SATA SSD, 128GB Toshiba PCIe x2 M.2 SSD (KBG30ZMV128G) gone cooking externally, 1TB Seagate 7200RPM 2.5" HDD (ST1000LM049-2GH172) left outside Monitor: 1080p 126Hz IPS G-sync

 

Desktop benching:

Cinebench R15 Single thread:168 Multi-thread: 833 

SuperPi (v1.5 from Techpowerup, PI value output) 16K: 0.100s 1M: 8.255s 32M: 7m 45.93s

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When you disconnect the 12V for the CPU, the motherboard is not aware that a CPU is installed so it blasts everything on, and everything connected to the CPU like the Chipset/RAM/PCIE are not working properly, so it could either be, one of them, the CPU/Socket, or just a defective Motherboard

Quote or Tag people so they know that you've replied.

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