Question Computer won't start

[Tchamber]

Hey guys. I've been building a new computer for my nieces, and have had nothing but trouble. When I first got it all put together, I hit the power button and nothing happened. I flipped the switch on the PSU, and hit it again. The CPU fan spun about a whole revolution. I thought it must be the PSU, so I replaced it. Same issue. I replaced the motherboard. Same issue. I thought maybe it's the power button on the case. Replaced that, and still have the same issue. It has:
Asrock H470M-ITX/ac
i5-10400
WD Blue SSD
Lian Li Tu 150-WA Mini-ITX case
Silverstone 450W SFX SST-ST45SF
G.SKILL Ripjaws F4-2666C15D-16GVR

I would appreciate any input, I'm out of ideas.

 

[MalVeauX]

Heya,

Short the board's pins for power without the connection from the case (in case that little thing is the problem) and see if it stays on basically. Check the CPU that it's fully seated (in case its not fully seated) and that the cooler is seated properly and plugged into the CPU FAN pins (specifically) so that the board knows it has a cooler and will past that checkpoint in POST. Try and boot it without no drives, no nothing, just the CPU, RAM and board and see if it stays on through POST (even with no GPU). If it does, then put in the GPU. Try it out of the case just so you can ensure its not a short somewhere from bad contact in the case. Make sure the RAM is seated completely.

Very best,

 

[VirtualLarry]

There was another fellow on here that I assisted, he had built his first computer, and he did a fairly decent job, other than he mistakenly put the CPU fan heatsink plug into the CPU_OPT fan header on the board, rather than CPU_FAN. Make sure, if the system is powering up then immediately powering off, that you have the CPU heatsink fan plugged into the CPU_FAN connector on the board.

If you feel brave, but uncertain that you put the CPU in correctly (it is notched, so it should only fit in one way), you can remove it, after removing the HSF, and inspect the pins in the socket, and re-install. You will have to re-install thermal paste between the CPU heatspreader on top of the chip, and the heatsink (apply paste to heatspreader, then apply heatsink). If this seems too involved, save it as a last resort.

One other thing to try, on a fresh install, is powering everything down, unplugging the build, and using the CLR_CMOS jumper. (Two-pin means, that you need to short them together for a few seconds to clear the CMOS, three-pin varieties mean that you move them from "normal" position to "clear" position, and then wait a few seconds, and then move the jumper back to "normal" for operation), and then plug back in and attempt power-up.

If you have a 4-pin peizo speaker, plug that in.

 

[Tchamber]

There was another fellow on here that I assisted, he had built his first computer, and he did a fairly decent job, other than he mistakenly put the CPU fan heatsink plug into the CPU_OPT fan header on the board, rather than CPU_FAN. Make sure, if the system is powering up then immediately powering off, that you have the CPU heatsink fan plugged into the CPU_FAN connector on the board.

If you feel brave, but uncertain that you put the CPU in correctly (it is notched, so it should only fit in one way), you can remove it, after removing the HSF, and inspect the pins in the socket, and re-install. You will have to re-install thermal paste between the CPU heatspreader on top of the chip, and the heatsink (apply paste to heatspreader, then apply heatsink). If this seems too involved, save it as a last resort.

One other thing to try, on a fresh install, is powering everything down, unplugging the build, and using the CLR_CMOS jumper. (Two-pin means, that you need to short them together for a few seconds to clear the CMOS, three-pin varieties mean that you move them from "normal" position to "clear" position, and then wait a few seconds, and then move the jumper back to "normal" for operation), and then plug back in and attempt power-up.

If you have a 4-pin peizo speaker, plug that in.

I saw that post about the fan header. I'll double check that. Never had anything even show up on the screen, no install to redo.

 

[Steltek]

@VirtualLarry wasn't talking about a software install, he was speaking about the CPU installation in the hardware install.

That motherboard has two fan headers marked CPU_FAN1 and CHA_FAN1/WP. You want to make sure to use CPU_FAN1 (the /WP header is for a water pump or chassis fan only). It also has a two pin CLR_CMOS header, so the jumper should not be installed when you try to start the system.

Were it my system, I'd remove the NVMe drive and one memory module and then try to start it up (if it doesn't work, swap the memory modules and try again. Also, repeat the process using the 2nd memory slot). While troubleshooting continues, leave the NVMe drive and any other unnecessary hardware (i.e. LED strips, etc) out of the build.

If it still isn't working, I'd look at a memory compatibility issue. The modules you are using aren't on the Asrock motherboard QVL list and g.skill doesn't have that board in its online memory compatibility tool. The fact that the CPU fan spins once and stops could be indicative of a memory incompatibility, so it is probably worth swapping out for a different set (or try a single DDR4 module from another system if you have one handy for testing purposes).

As a last resort, pull the motherboard from the case. Set it up on a piece of cardboard with only the CPU/heatsink installed and a single memory module. Reset the CMOS memory by shorting the jumpers for a few seconds with a screwdriver or a jumper (removing the jumper when done), then hook up the PSU leads to the motherboard (you don't have to remove it from the case - since you've replaced it once, it likely isn't the problem). Try to short the power switch pins on the motherboard with a screwdriver and see if it posts. If it does, you had a grounding issue in the case.

If it isn't posting by this point, you have to consider you may have a dead CPU. I left this for last because it is extremely rare, but it is possible. Before presuming it is dead, though, pull the heatsink, clean off the thermal material from the CPU, and remove the CPU. Carefully inspect the motherboard CPU socket with a magnifying glass for foreign material or bent pins. Also, check the pads on the bottom of the CPU as well to make sure something isn't obviously wrong with it.

 

[Tchamber]

So there is no CPU_OPT on my board. And the CPU fan was indeed plugged into the CPU fan header, not a chassis fan header.

 

[DooKey]

Not sure how experienced you are with building systems so don't take this wrong.

Make sure you plugged the 8-pin CPU auxiliary power plug into the top left of your board. Make sure it and the main PSU connections are snug in the board.