Help me diagnose: PC powers on, fans spin, no output, no beeps

[GravyMonster]

My PC has been working flawlessly for a year, until last night. Turned it on to play some games and it's not responding. The fans spin up, lights appear on the MB, AIO, RAM and GPU but I get no video output at all. Code on the motherboard is 'A0' which Google says means the system has posted and has transferred control to the OS.

Spec:
8086k
32Gb Corsair Dominator (2x16)
Maximus Hero X
H115i AIO
1080Ti
1Tb NVME

What I've tried:
- Different GPU (GTX980)
- No GPU, onboard HDMI through MB
- Different monitor
- 1 stick of RAM instead of 2 (trying both sticks individually)
- Removing RAM completely just to check if it gave a different result which it did, code on MB was '53' which indicates a RAM problem, as expected
- Clearing CMOS

Same result, fans and lights come on, but no output. I'm suspecting dead CPU or MB, but the A0 code is confusing me - surely this would not give a 'OK' code if there was a issue with the core of the system?

The only other CPU I could use is a i5 7600, but I don't think this is supported. I'll try it when I get home tonight anyway.

Does anyone have any other ideas what this could be before I'm forced to splurge on a new CPU/MB?

 

[Jay85]

If you've tried ram but still no output i would try no gpu and connect direct to the motherboard for IGPU output and see if it posts next.

 

[LuckyBenski]

The only other CPU I could use is a i5 7600, but I don't think this is supported. I'll try it when I get home tonight anyway.

Correct, your board will support 8th and 9th gen CPUs but not that as it's a 7th gen.

Also, just to check, have you ruled out the display cable?

Is there any sign the system is booting? In the before times you'd have a HDD activity light

 

[GravyMonster]

If you've tried ram but still no output i would try no gpu and connect direct to the motherboard for IGPU output and see if it posts next.

Thanks, yes, I did try that too - still no output. I'll update the OP

Correct, your board will support 8th and 9th gen CPUs but not that as it's a 7th gen.

Also, just to check, have you ruled out the display cable?

Is there any sign the system is booting? In the before times you'd have a HDD activity light

Thanks for confirming that the 7600 isn't going to help, saves me wasting time. And yeah, I tried a couple of different cables as I have multiple monitors setup, HDMI and DP.

There are signs the system is booting, the HDD activity light on the case flickers, and the code display on the MB cycles through various different codes as the system 'starts' until it settles on A0. I haven't checked any of them individually, but I assumed they were all ok as it ended on A0. The fans also start at full speed and then settle to normal fan curve speed after 10-15 seconds.

 

[Jay85]

Thanks, yes, I did try that too - still no output. I'll update the OP


Thanks for confirming that the 7600 isn't going to help, saves me wasting time. And yeah, I tried a couple of different cables as I have multiple monitors setup, HDMI and DP.

There are signs the system is booting, the HDD activity light on the case flickers, and the code display on the MB cycles through various different codes as the system 'starts' until it settles on A0. I haven't checked any of them individually, but I assumed they were all ok as it ended on A0. The fans also start at full speed and then settle to normal fan curve speed after 10-15 seconds.

Least you can rule out its not your gpu then, i wouldn't rule out the Ram just yet as it is weird behaviour to be booting to OS but not display output. If you have a spare set of ram somewhere i would try that next. Disconnect anything that doesn't need to be connected as well including any USB connections, internal and external. You want the bare basics connected to post.

 

[GravyMonster]

Still no joy this evening, removing everything but CPU and memory and still no post. A friend is going to bring over his 8600k at the weekend to determine if it's the CPU or motherboard, and then I'll try and find some replacements.

Appreciate the help @Jay85 @LuckyBenski

 

[demonix]

Still no joy this evening, removing everything but CPU and memory and still no post.

I think your google-fu failed as according to the motherboards user manual the A0 code doesn't mean that everything has checked out and control is being passed to the installed operating system as code A0 is shown as IDE initialisation has started meaning that it is stalling while detecting drives since if I'm reading the q-code list correctly you should be getting code AD which has the description "ready to boot event" meaning that would be the point where it would be passing control to the installed operating system.

With that it's possible that the problem is with the motherboard (specifically with the chipset) so if you still get the same results with your friends 8600k then it'll be a 100% certainty that there has been a failure on the motherboard.