PC fans flash and machine won't boot

[dct001]

I will press the power button on my PC and the fan's RBG will flash and start to spin then stop. This will happen a couple of times and even continuously if I hold the button. If I wait a couple of seconds and do it again and the same issue happens

 

Is this a motherboard, PSU, or CPU issue. Please help

Specs:

• Windows 10 64 bit
• Z390-A PRO (MS-7b98) [BIOS 1.BO 8/10/2020 UEFI]
• Intel i7-9700K at 3.6GHz
• 2x8GB OLOY DDR4 RAM 3000MHz but runs at 2700MHz
• NVIDIA GeForce RTX 3070
• Silicon Power 1TB - NVMe M.2 PCIe Gen3x4 2280 SSD boot
• WD green 1TB storage drive
• Gigabyte 750W 80+ gold PSU

[Yua]

Hi, welcome to the forums. Is this the first PC you have built?

 

Have you tried resetting your CMOS settings?

 

With your computer off but still connected, grab something metallic, like the tip of a screwdriver, and connect these two pins for 10 seconds.

 

Then try turning it on again to see if that works.

 

 

[Yua]

Also, your motherboard has debug lights right above the 24 pin connector; these are in this order from top to bottom: CPU, DRAM, VGA, and BOOT.

Tell me if one of them lights up.

 

 

 

[boomrocker]

Is this a new build or something recently changed?

 

 

Pg.36 of your motherboard manual shows this has debugging lights, what do these show? (Pua beat me to it while typing!)

This might tell you if you need to reseat CPU or memory bit could try regardless.

 

If it's a new build go through cables again making sure everything is plugged in right place and check there's no loose screws or anything grounding the motherboard to chassis.

 

 

 

 

[dct001]

@Yua @boomrocker

I have had this build for maybe 2-3 years. I have never had any issues until now. The quick debug flashes CPU along with the fans before just going dead. I have not tried the CMOS yet, but will update you all

 

When I used a screwdriver it would either flash LED and fans twice instead of the usual once or not at all. 

Also, it is now just repeating the flashing. I added a video for a better explanation. I turned off PSU after the video and turned back on and the system booted for 30 sec.

 

IMG_8558.MOV

[dct001]

Here are more videos of what is happening. Flash warning I'm sorry the fans are bugging out. You can see the debug light and what happens when it is stuck in the loop. When I touch the pins, as @Yua said when it is happening the loop stops and the PC is completely off

 

 

[Yua]

Your computer seems to be stuck in a power loop.

 

Do you have a spare PSU? If you do, please swap and see if anything changes; if not, you are going to try a very rudimentary test for the power supply.

First, disconnect all the power supply cables from your computer.

 

Grab the big power connector that hooks into the side of the motherboard and use the little retainer clip as a reference to know how to hold it, like in the image.

Grab a paper clip or a piece of cable and connect pins PS-on with any pin that says Black/Ground.

 

So if you were to hold the connector with the plastic clip facing your right, like in the picture, you would need to connect the pin, row 4, column 2, to either the one above or below.

 

Once you do that, you should see your power supply turn on. Which would indicate it is working. If you have a multimeter, you could check the pins to see if they match the voltages in the picture.

If you don't, we can just maybe expect the fan of the power supply to keep spinning. This could also not be the case since some PSUs run the fan at 0 RPM when there's little load.

 

27 minutes ago, dct001 said:

When I touch the pins, as @Yua said when it is happening the loop stops and the PC is completely off

This is expected since shorting those pins discharges the motherboard.

 

[dct001]

@Yua I did the paperclip test and the PSU turns on, and the fans run for a bit then stop. About an hour ago, after running all the tests my PC booted to BIOS and reset it. It seems to be running fine, but I hope it's not just a temporary fix. I really appreciate all of your help, it has been massively helpful 

[dct001]

@Yua After a couple of days, the problem came back. Is it a faulty part? I may have to take it to a PC repair store

[Yua]

Thats disheartening.

Anything previously said here helped on bringing it back to life?

[dct001]

@Yua Resetting the CMOS worked again, but it died once more. I reset the CMOS again, and it won't even flash anymore. I think it may either be RAM, Motherboard, or PSU. I don't think the GPU bc it wasn't artifacting, and the CPU wasn't running hot. Not sure

[Yua]

When you say it died again. Do you mean that the computer suddenly turns off while you are using it?

We can definitely do a lot more to diagnose what's wrong with it if you are willing to do it.

Disconnect the GPU and take it out completely. Don't put it back just yet.

Take the ram out and reseat them. Try different combinations, like leaving only one of them at the time.

Try and see if it posts correctly.

[dct001]

When I say it dies, I'll push the power button, and it'll either do the flashing LED or sometimes won't even respond to the input.

The PSU will click after turning it off during a boot loop too for a couple sec. I'll try to get a video and try the combos mentioned above tomorrow 

Thanks!! 

[dct001]

@Yua When I am diagnosing it should I take GPU out first or RAM? And for ram would I leave one of the sticks in the first slot or both?

[Yua]

First of all you want to eliminate the possibility of it being a bad component and not just a bad contact. So you want to make the motherboard turn on consistently.

For that I would start taking the gpu out and see if it now turn on consistently.

If it's still having issues turning on, then you will remove one ram stick and leave only one, swapping it from slot to slot and testing powering up the pc to see if it posts correctly.

How do you know if you have a good boot even without a GPU?

Your motherboard has diagnostic leds. And if you see the bottom led turn on and then turn off it means it booted into the OS.

[dct001]

On 12/16/2023 at 1:38 PM, Yua said:

First of all you want to eliminate the possibility of it being a bad component and not just a bad contact. So you want to make the motherboard turn on consistently.

For that I would start taking the gpu out and see if it now turn on consistently.

If it's still having issues turning on, then you will remove one ram stick and leave only one, swapping it from slot to slot and testing powering up the pc to see if it posts correctly.

How do you know if you have a good boot even without a GPU?

Your motherboard has diagnostic leds. And if you see the bottom led turn on and then turn off it means it booted into the OS.

I haven’t been able to do this but now I’m getting artifacting on boot screen but on nothing else. It hasn’t “died” like before yet but I’ve seen this is a sign of either a bad monitor or bad CPU if nothing else has issues. My cpu is running at around 100% on EA FC and even crashed yesterday. Would you still recommend me testing as mentioned. I’ll do this when I get home from work

[dct001]

@Yua would it be helpful for you for me to run a benchmark before I shut down and run tests?

 

UserBenchmarks: Game 142%, Desk 99%, Work 133%
CPU: Intel Core i7-9700K - 97.9%
GPU: Nvidia RTX 3070 - 146%
SSD: Spcc M.2 PCIe SSD 1TB - 205.8%
SSD: WDC WDS100T2G0A-00JH30 1TB - 43.6%
RAM: Unknown CL16-20-20 D4-3200 2x8GB - 85.4%
MBD: MSI Z390-A PRO (MS-7B98)
 

 

PSU is also acting funny. When I turn it off and hit the power button to discharge, it clicks, but if I plug it back in and turn it on, the machine will turn on without me hitting the power button. 

 

Disconnected PSU and left alone for a while, unhooked GPU, reconnected PSU and turned it on and the machine went back to clicking and flashing fans as before. The LED for boot didn't even turn on