Finished build won't boot, one LED working on mobo

Nine Blue Lances

Reputable
Sep 3, 2015
3
0
4,510
Hello everyone,

I finished my build, plugged in the power cable and turned the PC on. Case LEDs and graphics card LED etc were all working properly for 0.5~1 second. Then the PC turned itself off. The system doesn't boot anymore since then.

I think the major problem is that I booted the system once without the CPU power cable attached (this was stupid, hadn't checked properly). Turning the system on now won't do anything (with or without the CPU power cable connected). No case LEDs, no GPU LEDs, no fans, etc.

Just one small LED on the mobo next to the 24 pin power cable slot is lit when the PSU is turned on. This means, as far as I know, that the PSU is not the problem.

What I tried:
Reversing the POWER SW cable in the JFP1 slot, didn't work.
Checked the cable that is attached to the case boot and reset button, seemed OK.

Specs:
Intel Core i5-6600K Boxed
MSI Z170A GAMING M5
MSI GeForce GTX 970 GAMING 4G
Seagate Desktop HDD ST2000DM001, 2TB
NZXT H440, Black
Scythe Mugen 4 PCGH Edition
Crucial Ballistix Sport BLS2C8G4D240FSA
Cooler Master GM G650M
Samsung 850 EVO 250GB

Could booting the PC without CPU power cable harm the system?

Thanks in advance
 
Solution
Try remove the CMOS battery, wait for 10min, put it back and try boot the pc again. Without cpu power cable, the system will not boot, and that will not kill the cpu or MB, because the cpu will not get enough power to boot.
Try remove the CMOS battery, wait for 10min, put it back and try boot the pc again. Without cpu power cable, the system will not boot, and that will not kill the cpu or MB, because the cpu will not get enough power to boot.
 
Solution

Nine Blue Lances

Reputable
Sep 3, 2015
3
0
4,510


Thanks a bunch! This worked!