Question Replaced PC motherboad, now the PC is possessed

exploding_psu

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Evening,,
I've driven myself into a wall, I'm desperate

TLDR : PC barely show any signs of life except during very specific hours

First of all, obligatory system specs :

CPU : Ryzen 5 2600
Mobo : B450 Steel Legend (was MSI X370 SLI Plus)
RAM : T-Force Delta R DDR4 3000 32 (16x2) GB RGB
GPU : Yeston RX 6800 XT
SSD : Samsung PM1725a 1.5 TB
HDD : An old 500 GB Seagate Momentus Thin
PSU : Seasonic S12G Gold
Cooler : Cryorig H7 QL
Case : some random chinese $20 case

So long story short, I have this B450 Steel Legend motherboard just sitting around upstairs in an unused PC, so I decided to replace my own PC's motherboard with the B450. The B450 worked well before this, it used to be installed on my cousins PC who since have moved (before I installed the B450 motherboard into my PC, I tried booting up my cousin's PC, no problem).

Anyway, here's the head scratcher :
After installing everything, the PC refuses to boot. When the PSU is switched on, only the RGB lights on the motherboard lights up (and the cooler lights), but the PC won't turn on at all. Power button, restart button, even shorting the front panel headers does nothing. It just refuses to boot under any circumstances. I'm sure the other parts in the PC is fine, it's working just fine before I replaced the motherboard with the B450 just short moments ago.

The weird part is, the PC would turn on by itself for absolutely no reason near midnight. Like I said, it's possessed I'm telling you. When the PC mysteriously turns on, it works fine. The power button work, the reset button too, RGB lights etc. Everything works perfectly. I can shut it down and the PC would turn on with the press of the power button with no problem at all, as long as it's near midnight. Then the PC would refuse to boot again when it's not at the "magic hour", showing no signs of life (except the RGB lights), with the power button / header not functioning, nothing turns it on. Then come midnight (around 11 pm) and it would boot by itself and starts working again until I shut it down outside the "magic hour", in which the cycle continues.

I've never seen this sort of problem, it looks like the PC is in some sort of timer in which it will boot at certain time but not outside it. This means everytime I wanted to use the PC, I would have to wait until "the demon" kicks in and boot the PC for me.

I've tried everything by the book, triple checked everything (trust me, I had 2 days to work with it), some things I've tried :
  • Tried different CPUs (R5 2600, R3 2200G, R3 1200)
  • Different RAM kits (8GB Tforce, 32 GB Tforce, and everything in between)
  • Different SSDs (an Adata and my Samsung)
  • Different GPUs (6800XT and Vega 56)
  • Different PSU (Seasonic and a FSP PSU)
  • Different case (including no case)
  • Resetting BIOS countless times, removing CMOS battery
  • Rebuilding the entire thing from scratch, 3 times
  • Using different screws to screw the motherboard to the case
  • Trying to boot with the least part installed (CPU and the cooler, CPU and RAM, CPU, RAM, and GPU, and all sorts of combinations)
  • Reinstalling the motherboard back to my cousin's PC (same symptoms weirdly)
The only thing I haven't tried is trying a different cooler (I don't have a spare). I've tried everything in the first 3 pages of Google search including all sort of usual remedies. Nothing worked. It's like the actual parts are OK (proved with the fact the PC runs perfectly when it randomly DOES turns on), the problem is the PC only want to turns on at specific times, by itself.
Reinstalling my old X370 motherboard into the PC boots it up normally, so again I know it's not the other parts. Heck, the B450 motherboard was a reliable workhorse when my cousin was still using it, it ran almost 24/7 no problem (he rarely shut it down). The entire problem only appeared right after I "transplanted" the B450 into my PC.

Any input is welcome, I'm starting to think the moon phases has something to do with the ability of my PC to boot.

EDIT : Accidentally wrote "removing CMOS clock" instead of "removing CMOS battery",, fixed
 

exploding_psu

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First things first. Did you reinstall Windows after the motherboard change? If not then this is 99% of your issues. Full wipe and reinstall after any motherboard change.
No, I haven't reinstalled Windows after the motherboard change. I'll make sure to reinstall it next time the PC turns on (it's 9 in the morning now, so I have an entire day to wait)..
That being said, are you sure it's the Windows? After all, the PC won't even POST currently.
 

ex_bubblehead

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Not Posting is a different problem, likely a power supply issue. This is not a place to go cheap. However, Windows is absolutely not designed (never was) to be moved from one motherboard to another. Though Windows 10 is better about this than previous versions it's still not perfect and problems absolutely will be encountered at some point down the road.
 
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exploding_psu

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Not Posting is a different problem, likely a power supply issue. This is not a place to go cheap. However, Windows is absolutely not designed (never was) to be moved from one motherboard to another. Though Windows 10 is better about this than previous versions it's still not perfect and problems absolutely will be encountered at some point down the road.
That was my first thought too, the PSU might be the problem. But, recall the PSU works fine beforehand when I still had the old X370 motherboard installed. Replacing the PSU with another (known good) PSU the problem still remains, the B450 motherboard won't boot. It just doesn't make any sense in my opinion that the PSU is the problem if it runs well with different motherboard.

I'm going to need a stronger paracetamol after this, man.
 

exploding_psu

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First of all I'd like to say this post is an update of my post right here. Rather than necro-ing that old post, I figure out I'll write a new post with recent developments. If this isn't allowed on the rules, I'm sorry, I didn't mean any ill will, let me know and I'll delete this one.

This is going to be a long post, I try to write as much details as possible, after all "the answer you get is only going to be as good as your question"

TLDR : Computer can only be turned on between 9:30 PM until around midnight. Refuses to turn on at all outside those hours. Computer works completely fine once it does turn on.

First of all, obligatory system specs :

CPU : Ryzen 5 2600
MB : B450 Steel Legend (was MSI X370 SLI Plus)
RAM : T-Force Delta R DDR4 3000 32 (16x2) GB RGB
GPU : Yeston RX 6800 XT
SSD : Samsung PM1725a 1.5 TB
HDD : An old 500 GB Seagate Momentus Thin
PSU : Seasonic S12G Gold
Cooler : Cryorig H7 QL
Case : some random chinese $20 case

I replaced the motherboard of my computer to a B450 Steel Legend pulled from another computer which was working fine. Since then, my computer wouldn't turn on except during specific hours.
The PC used to turn on by itself after I installed the B450.
At first I thought the PC would turn on randomly at midnight. After observing the PC for several days, the PC actually turns on consistently at around 9:30, give or take 15 minutes.
After updating the BIOS in a bid to solve the problem, now the computer ceases turning on by itself, but can still only be turned on at the hours mentioned above.

Behavior :
  • PC can only be turned on between 9:30 PM until around midnight (say 1:00 AM). This behaviour is consistent, in that the PC can consistently be turned on as long 9:30 PM has passed.
  • Outside the "magic hour", PC refuses to turn on at all, whether by pressing the power button, reset button, or shorting the front panel header. Absolutely no POST
  • But after 9:30 PM, the PC can be turned on easily with the power button. The PC will then works problem-free, rock solid, stable, no error at all. PC can be restarted normally, shut down and rebooted, BIOS accessed, put to sleep or hibernate, nothing's broken. Just like a normal PC
  • Once it passes the 1:00 AM mark, if the PC is in anyway shut down (or merely put to sleep), the PC won't turn on again, even though it works fine just seconds ago
  • If the PC is turned on and left alone, the PC runs indefinitely until it's manually turned off outside the 9:30-midnight hours in which it refuses to turn on (in other words, as long as the PC isn't shut down, it will keep running)
  • When the PC's power is connected and PSU switched on, the motherboard's RGB and the cooler RGB light up, despite the PC being in shut down state (I read this is normal behaviour in that RGB lights will remain on as long as the PC receives power)
I've scoured the forum and the web for people with similar symptoms, and I've listed here from the most to the least probable, and steps I've taken to test / remedy the problem. Development is quite slow, considering the PC only turns on ONCE at midnight, so if I miss the magic hour I literally have to wait for the next day to give it another shot.

1. There's a short somewhere in the PC
I've read someone here had a similar problem caused by a shorted USB extension in his (I assume) PC. Another post stated the motherboard was touching the standoff thing. To test whether my PC has a short somewhere, I've tried :
  • Using different screws to screw the motherboard to the case
  • Trying a different case (2 case, both unnamed chinese parts)
  • Switching the standoffs
  • Running the PC entirely outside the case (breadboarding)
Obviously nothing worked. Even outside the case with the setup placed on top of a motherboard box, PC only turns on around midnight, so I can eliminate electrical short as a potential cause for the problem.

2. PSU problem
Of course if a PC has problem turning on, the PSU might be the culprit. I've tried :
  • Using different known good PSUs (by known good, the PSUs I tried were pulled directly from working computers). Tried 3 PSUs, a seasonic, an FSP, and a Corsair. Same symptoms
  • Trying different cables for the PSUs (tried like 5 different cables)
  • Installing the PC PSUs on different computers (the PSU works fine)
There are two things that makes me think it's not a PSU problem. First, the PC's PSU runs fine when installed in another computer. Second, when the computer does turn on it works fine, I can run demanding programs (I tried Prime95 and 3DMark) without the traditional "failing PSU symptoms" like the PC shutting down or anything. PC is rock solid when it works. I reckon if the PSU is problematic it would make the PC refuse to turn on at all or at least shut down the PC when it's hit by demanding application (I've seen a fair share of failed PSUs in my time, just read my username. This just isn't it)

3. Front panel header set up improperly
Someone said that a RESET front panel cable connected to the wrong header might send the PC to an infinite bootloop. I've 4x checked the motherboard guide to make sure I connected the front panel cable header thingy properly. The reason why I'm sure the front panel is installed properly is when the PC runs, the power button, reset, all the LEDs works fine. Besides, outside the 9:30-midnight time window the PC won't turn on even if I have nothing connected to the header and tried to short the power pins. On the other hand, the PC have turned on by itself with nothing connected to the front panel header at least once when the clock hits 9:30 (before the BIOS update, when the PC still had a habit of turning on by itself).

4. RAM problem
Maybe the RAM is faulty? Tried 4 sets of different sticks (32 GB Tforce (the main one), 8GB Tforce, 8GB Apacer, 8GB Avexir). Still won't boot outside the magic hour. When the PC does turn on, the 32 GB RAM installed on the PC is detected just fine, XMP is functioning, no problem in memtest86, task manager reads all the 32 GB, it's healthy.

5. BIOS problem
Maybe the BIOS is somehow corrupted? I've tried :
-Resetting all BIOS settings from the BIOS "menu"
  • Trying to enable / disable secure boot
  • Switching around boot order settings
  • Basically trying every setting on that menu
  • Resetting the BIOS by shorting the CMOS_RESET header
  • Removing the BIOS battery
  • Doing all of the above and holding the power button to "drain" the power
  • Updating the BIOS (3.40 to 3.50)
I updated the BIOS a couple of nights ago, and the PC now stopped turning on by itself. I now have to press the power button to turn it on, of course only after 9:30 PM. If the BIOS settings were the culprit, I've resetted it countless of times (and updating the BIOS resets it to default state anyway according to ASRock), but the problem remains. Heck, at this point the PC's date and time is all wrong ,testament to how many times I've reset the BIOS.

6. Some parts (SSD, CPU) is faulty
This is the big one. What if the CPU is faulty? I tried installing the CPU on a different motherboard (A320 ASRock) in different computer, and it boots no problem at all. Tried to install different SSDs and HDDs (a Samsung, an Adata, and a Seagate HDD) as a boot drive, still same problem. Also tried turning on the PC with barely any part installed (just the CPU, cooler, one stick of RAM, and a GPU) and no dice. I expected the PC to at least POST with that setup, but no. It's "9:30 PM or die"

7. CPU is overheating
I'm not sure the CPU overheating is the problem, as the PC won't even turn on so how can the CPU gets overheated? I've replaced the cooler paste and even the cooler (Cryorig H7 and 2 stock AMD coolers, also tried to connect the fan to different FAN headers) for good measure. When the PC turns on, the PC idles around high 30 C, and 10 minutes of Prime95 only raises the temp to around 60-70C, which I think is still a safe temperature. I've spent an entire tube of deepcool just trying to make sure it's not a cooling problem.

8. GPU problem
Tried 5 different GPUs for the sake of elimination (6800XT, Vega 56, 1060, 970, 2070). PC has booted with the 6800XT and Vega 56, and as I said before no problem at all once the PC runs. 3DMark stability tests passed (around 98%), and I can game for hours

9. Corrupted Windows
I was told to reinstall Windows in the last thread. While to be honest I still don't believe Windows is the problem (as no matter how mangled the installation is, the PC should at least POST), I reinstalled the Windows 11 for good measure some days ago when I got the chance. Now I have "activation failed" problem, but as this is simply a matter of me reentering my product key, it's not a pressing concern this time. And no, even after reinstallation the PC only boot during that specific hours. If the old Windows had, say, somekind of schedules or timer, it should be gone by now.

10. The surge protector has some problem
Okay it's wild guess at this point. The PC is connected to a surge protector, maybe it's the problem? I'm sure it's not the surge protector. It's a simple one without any timer and I've tested it by cconnecting myriads of electronics from 5W phone charger to 2000W vacuum cleaner and everything in between, and they all run fine.

The short version is : PC works fine, all the parts are functioning. It's simply wants to be turned on ONLY at very specific time for some reason.

Obviously something is up with the B450 motherboard. If I reinstalled my old X370 into the setup, PC boots fine just like it's always been. Pairing different CPUs with the B450 motherboard (tried R5 2600, R3 1200,, R3 2200G) have no effect, it still only turns on after 9:30. What puzzles me is WHY the fully functioning B450 motherboard ONLY wants to be turned on after 9:30 PM. It's like it's possessed or allergic to daytime or something.

This is the second weirdest PC problem I've ever seen, beaten only by my friend's Core 2 Quad PC which can only be turned on when the full moon is out,, but that's another story for another day.

Sorry if I put out this massive wall of text that sounds like a ramble of a madman and gave you a headache, that's why I put several TLDRs, I simply ran out of ideas, and I'm tired of rebuilding the PC and switching parts. The 20-pin is an absolute trouble to remove.
ANY input is welcome.
ANY input is welcome.
Thank you
 
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exploding_psu

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I would install the old motherboard and call it a day. Going from a x370 to B450 chipset is not really an upgrade rather side grade.
If the B450 does same thing on the other PC you can safely assume the board is faulty. I know it was fine before, but it seems it is not fine now. Happens.
Indeed, after wrestling with the situation for weeks, I'm throwing in the towel

I reinstalled the X370 motherboard back. It turns on without a hitch. Even the Windows activation problem got resolved by itself.
I just don't have the will to keep troubleshooting the B450 motherboard.

The problem is solved, by going back to an older known-good motherboard. Not the kind of "solved" I wanted, but all those extra features the B450 has is useless if it can't even turn on.

For the time being, I'll put this weird problem in the back burner. Maybe I'll give it a try again sometime in the future. Or maybe not. I've called ASRock about the situation, and they asked me to bring the board to their service center here, which is like 700 km from where I live. They snake around mentioning out-of-warranty, "unclear explanation of the problem", "unsupported platform", "product not registered", and whatnot.

If the board is indeed problematic, this would be the second dead ASRock motherboard I've bought (the first one, an A320, stopped working after installing a new RAM. Reinstalling the old RAM didn't work). Maybe I'm just unlucky with ASRock boards. The X370 MSI has been a rock solid performer even though I bought it secondhand and the previous owner ran it in overclocking competitions.

Thank you for the replies anyway, really appreciate it.
 

exploding_psu

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There is a built in POS where it can be told to turn on or off at certain times of the day. Pull the battery, reset the CMOS, reattempt.
I'm sorry, but I don't know what a "POS" is, is that a setting on the BIOS? If it is, I'm 100% sure there isn't any setting / switch / menu on the BIOS that I can set to turn on / off PC at a certain specific time. The only one I can find is allow devices to turn on PC based on RTC clock or turn on PC after power failure. I've seen the BIOS so many times I've memorized the menu. But I'm ready to stand corrected if I indeed missed it.

What I can tell you is I've pulled the battery and reset the CMOS countless of times. I've even tried different batteries, leaving the PC off without CMOS battery overnight while keeping the power button pressed to "drain the power", and all sorts of shenanigans. No dice. Trust me, I've tried so many methods to clear the BIOS.

And it perplexes me, if there's a setting in the BIOS that prevents the PC from turning on, that setting (whatever it is) should be reset when the CMOS is reset. But no, the problem is still there, even after the BIOS has been noticeably reset (e.g. the BIOS shows the wrong time). If it's indeed a device preventing the PC from firing up, the motherboard should at least turns on when I installed it on a different PC, which had entirely different parts installed. It feels like the motherboard has a hidden timer which can't be reset even after a BIOS reset (or even BIOS update, which should reset all BIOS settings per ASRock's own guide)

A very peculiar case indeed.
 
I'm sorry, but I don't know what a "POS" is, is that a setting on the BIOS? If it is, I'm 100% sure there isn't any setting / switch / menu on the BIOS that I can set to turn on / off PC at a certain specific time. The only one I can find is allow devices to turn on PC based on RTC clock or turn on PC after power failure. I've seen the BIOS so many times I've memorized the menu. But I'm ready to stand corrected if I indeed missed it.

What I can tell you is I've pulled the battery and reset the CMOS countless of times. I've even tried different batteries, leaving the PC off without CMOS battery overnight while keeping the power button pressed to "drain the power", and all sorts of shenanigans. No dice. Trust me, I've tried so many methods to clear the BIOS.

And it perplexes me, if there's a setting in the BIOS that prevents the PC from turning on, that setting (whatever it is) should be reset when the CMOS is reset. But no, the problem is still there, even after the BIOS has been noticeably reset (e.g. the BIOS shows the wrong time). If it's indeed a device preventing the PC from firing up, the motherboard should at least turns on when I installed it on a different PC, which had entirely different parts installed. It feels like the motherboard has a hidden timer which can't be reset even after a BIOS reset (or even BIOS update, which should reset all BIOS settings per ASRock's own guide)

A very peculiar case indeed.
That is most curious. Once the BIOS gets reset, the time gets reset. So how would it know it's 9PM -> Midnight? (The only time you say it will boot)

See if there is a Wake On Lan component turned on. POS (power on startup) is based on the RTC clock. There's also a PDS (power down shutdown) But this is an extremely rare exposed feature. They are meant more for specialty appliances.

Maybe your house is having electrical issues causing the Power Good signal to return Low (off) to the PSU due to low power during the day.
 

exploding_psu

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That is most curious. Once the BIOS gets reset, the time gets reset. So how would it know it's 9PM -> Midnight? (The only time you say it will boot)

See if there is a Wake On Lan component turned on. POS (power on startup) is based on the RTC clock. There's also a PDS (power down shutdown) But this is an extremely rare exposed feature. They are meant more for specialty appliances.

Maybe your house is having electrical issues causing the Power Good signal to return Low (off) to the PSU due to low power during the day.
Sorry for the extremely late reply, life stuff.
I have a theory that somewhere buried in the motherboard there's a hidden timer which can't be reset no matter what. This is how the PC can consistently boot at 9:30 PM. There's no way to prove this of course, but that's the only thing I can think of

THAT being said though, while the motherboard usually turns on at or around 9:30 PM, last night it turned on at 6:30 PM instead. And instead of booting normally, it got stuck on a bootloop. The PC turned on by itself (again) and rebooted for like an hour before it loaded the desktop. I didn't touch it at all for the whole process. The motherboard is just getting more unpredictable as time goes on.

Try turning off your ac during the day.. you might have a wiring fault contributing to the daytime instability.
We never run the AC during the day, and the room the PC is at doesn't have an AC (and it's connected to a different circuit from the AC, someone here actually helped me to figure it out).

Now, I felt like I've exhausted all options, and while I appreciate your help, I think we'll just put this issue to rest. I've reinstalled the old motherboard to the PC, and it runs fine now. I think I'll just consider this issue "solved" by switching the motherboard entirely. Spending like 3 weeks to troubleshoot a motherboard is starting to look not worth the time to me...
 

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