Hit power buton, CPU fan spins for half a second then stops, Spin-and-stop forever. No booting.

[Vicaris]

My system-
CPU: i5 4440
RAM: Kingston HyperX Fury 8GB
GPU: HD 7750
MoBo: Asus B85M-E/BR
PSU: Corsair CX500

How the problem started:
First time, I wasn't near the computer but I know it just reset on its own.
Second time, shortly after this reboot, windows froze and the screen was blinking fast like it were switching resolution.
Tried restarting, It just froze at the mobo splash screen. It did not respond to hitting Del or F2.
Fourth time restarting, the CPU fan starts to spin and then it stops less than a second later, it keeps going on like this forever. I have tested my PSU and I believe it is working fine.

Things I have tried, in this order:
-Changing RAM slots.

-Removing mobo battery for several minutes.

-Removing GPU.

-Cleaning the hardware.

-Removing every component and putting it back together.

-I've tested my PSU on another machine. A much older machine with an Intel Celeron e1500. My PSU worked just fine on that machine. I've also taken the older machine's still functioning PSU (it was some cheap thing I don't remember the brand) and used it on my machine. I had the same result as with my PSU. Of course, this test was done without having my GPU connected. It was just CPU and RAM.

-Coming to Tom's Hardware forums and making a post about this.

What I'd like:
-Some guidance on how to check if the problem is in my motherboard without requiring spare parts.
-Some help as to what could be causing this problem.

Thanks in advance.

 

[Yamitime]

If I was a betting man I would put a large amount of money on the PSU being faulty even though it seems ok on another system.
Do you get the good power single beep when you press button (this is presuming you have a buzzer or speaker attached to MB) ?

 

[skibo1219]

will it cold boot? leave it sit for several hours.

do you have a spare CPU? will the fans power up without the CPU and RAM?

have you tried to clear CMOS by either switching the jumper or pulling the batter for 1 min?

 

[Vicaris]

Sorry, I don't have a motherboard speaker. No beeps for me.
Also no spare CPU.

Skibo, do you mean the PSU fans? Those power up without CPU and RAM.

Also, what do you mean for cold boot? Because I have waited several hours before trying to turn it back on after putting everything back together.

 

[Vicaris]

If I was a betting man I would put a large amount of money on the PSU being faulty even though it seems ok on another system.
Do you get the good power single beep when you press button (this is presuming you have a buzzer or speaker attached to MB) ?

Sorry, no speaker

 

[skibo1219]

no I meant fans directly connect to the motherboard, like the Heatsink fans on CPU_FAN and/or CPU_OPT.

Cold Boot is leaving your computer alone to cool off for a few hours.

did you reset CMOS via jumper or battery removal?

 

[Vicaris]

will it cold boot? leave it sit for several hours.

do you have a spare CPU? will the fans power up without the CPU and RAM?

have you tried to clear CMOS by either switching the jumper or pulling the batter for 1 min?

Nope, no spare CPU.

If you mean the PSU fan, yeah it powers up.

Also I've tried pulling the battery but not the CMOS clearing.

 

[Vicaris]

no I meant fans directly connect to the motherboard, like the Heatsink fans on CPU_FAN and/or CPU_OPT.

Cold Boot is leaving your computer alone to cool off for a few hours.

did you reset CMOS via jumper or battery removal?

I have done the battery removal and the cold boot by removing battery. The CPU fan spins for a few seconds then it stops. It just keeps doing that forever.

 

[Yamitime]

will it cold boot? leave it sit for several hours.

do you have a spare CPU? will the fans power up without the CPU and RAM?

have you tried to clear CMOS by either switching the jumper or pulling the batter for 1 min?

Nope, no spare CPU.

If you mean the PSU fan, yeah it powers up.

Also I've tried pulling the battery but not the CMOS clearing.

That basically does the same thing .
Could you steal the speaker from the other rig and connect it to this one?

 

[skibo1219]

take out the CPU and ram and try to power it, but leave the CPU fans connected.

 

[Vicaris]

will it cold boot? leave it sit for several hours.

do you have a spare CPU? will the fans power up without the CPU and RAM?

have you tried to clear CMOS by either switching the jumper or pulling the batter for 1 min?

Nope, no spare CPU.

If you mean the PSU fan, yeah it powers up.

Also I've tried pulling the battery but not the CMOS clearing.

That basically does the same thing .
Could you steal the speaker from the other rig and connect it to this one?

I will do that later today and then I'll get back to you. Not sure if the other machine has a speaker either.

 

[mjslakeridge]

When you pulled the CMOS battery, did you also unplug the computer from the wall outlet?

 

[Vicaris]

take out the CPU and ram and try to power it, but leave the CPU fans connected.

All right I've done that. I got the same issue. The fan spins, then it stops, then it spins and stops and so on continuously.

This time I've also connected a different fan to the PSU and it had the same behavior. But that's just when the PSU's 24 pin connector is hooked to the mobo.

However, if I trick the PSU to start using a paperclip, the fan connected to the PSU runs nicely.

I'm starting to think it's definitely the motherboard. This is not the first time a motherboard dies on me. I've had it happen 2 or 3 other times before. I used to think it was on account of cheap power supplies, but I'm starting to think it's the case or something. The case is the only component that's been the same throughout all the motherboard failures. I've once had a motherboard's capacitor blow.

So, summing up the discoveries so far:

My machine will behave the same regardless of the PSU I'm using.

My current PSU behaves normally on another machine.

I get the same behavior if the only thing hooked to the motherboard is the CPU fan.

If I connect the motherboard and the PSU and if I connect an auxiliary fan and the PSU, the auxiliary fan will behave the same as the CPU's fan. But if I disconnect the PSU to the motherboard and trick it to run using a paperclip, the auxiliary fan runs normally.

Everything leads me to think the problem is the motherboard. But you guys probably have more experience in this than I do.

 

[Vicaris]

When you pulled the CMOS battery, did you also unplug the computer from the wall outlet?

Yep

 

[Yamitime]

Have you put too many risers (brass type risers where the motherboard screws screw into) under the mother board causing a short to ground ?

 

[Vicaris]

Have you put too many risers (brass type risers where the motherboard screws screw into) under the mother board causing a short to ground ?

I do have more risers than there are screws. I have six risers, four screwed in, on a mATX board.. But I've had these risers there for a long time. Could they cause a problem just now?

 

[Yamitime]

Have you put too many risers (brass type risers where the motherboard screws screw into) under the mother board causing a short to ground ?

I do have more risers than there are screws. I have six risers, four screwed in, on a mATX board.. But I've had these risers there for a long time. Could they cause a problem just now?

Yes different types of motherboard have the holes in different positions so its possible some of the unused risers are touching the motherboard when they shouldnt

 

[Vicaris]

The holes were all aligned with the bracers and my machine had been running for over a year with those extra bracers.


Anyway I've tried a breadboarding setup to some strange results. Here's a log of my attempts.

1st - Just CPU fan. Got the start and stop behavior for a minute then I shut it down.

2nd - CPU fan and CPU, start and stop five-six times then the fan ran normally.

3rd - Same as before plus RAM. Start and stop, gave up.

4th - Same as before, this time it the fan kept spinning.

5th - Same as before but also hooked machine to a monitor. Just the usual start and stop behavior. I let it run for several minutes, nothing different.

So, I'm not sure it's a short circuit on the motherboard anymore. If it were a shortcircuit, this start and stop behavior shouldn't happen on a breadboard setup and it should be consistent.

 

[skibo1219]

take out the CPU and ram and try to power it, but leave the CPU fans connected.

All right I've done that. I got the same issue. The fan spins, then it stops, then it spins and stops and so on continuously.

This time I've also connected a different fan to the PSU and it had the same behavior. But that's just when the PSU's 24 pin connector is hooked to the mobo.

However, if I trick the PSU to start using a paperclip, the fan connected to the PSU runs nicely.

Spoiler

I'm starting to think it's definitely the motherboard. This is not the first time a motherboard dies on me. I've had it happen 2 or 3 other times before. I used to think it was on account of cheap power supplies, but I'm starting to think it's the case or something. The case is the only component that's been the same throughout all the motherboard failures. I've once had a motherboard's capacitor blow.

So, summing up the discoveries so far:

My machine will behave the same regardless of the PSU I'm using.

My current PSU behaves normally on another machine.

I get the same behavior if the only thing hooked to the motherboard is the CPU fan.

If I connect the motherboard and the PSU and if I connect an auxiliary fan and the PSU, the auxiliary fan will behave the same as the CPU's fan. But if I disconnect the PSU to the motherboard and trick it to run using a paperclip, the auxiliary fan runs normally.

Everything leads me to think the problem is the motherboard. But you guys probably have more experience in this than I do.

This really narrows down, eliminating a failed CPU too, the issue to 2 things. First it could be the MB, but lets go with one more test.

Remove the MB connection to your cases power and reset buttons and any other cables there, including speaker (if there) and any lights (prolly just HDD). Ideally would be to have a spare power button and cable to use here, or if the board has a power on button built onto it. Having neither, just plug your case power button back in, I dont suggest jumping it what anything else as you could short something else out. This will eliminate switches or accidental grounding. This also assumes your PSU is in perfect working-as-intended order.

 

[Vicaris]

take out the CPU and ram and try to power it, but leave the CPU fans connected.

All right I've done that. I got the same issue. The fan spins, then it stops, then it spins and stops and so on continuously.

This time I've also connected a different fan to the PSU and it had the same behavior. But that's just when the PSU's 24 pin connector is hooked to the mobo.

However, if I trick the PSU to start using a paperclip, the fan connected to the PSU runs nicely.

Spoiler

I'm starting to think it's definitely the motherboard. This is not the first time a motherboard dies on me. I've had it happen 2 or 3 other times before. I used to think it was on account of cheap power supplies, but I'm starting to think it's the case or something. The case is the only component that's been the same throughout all the motherboard failures. I've once had a motherboard's capacitor blow.

So, summing up the discoveries so far:

My machine will behave the same regardless of the PSU I'm using.

My current PSU behaves normally on another machine.

I get the same behavior if the only thing hooked to the motherboard is the CPU fan.

If I connect the motherboard and the PSU and if I connect an auxiliary fan and the PSU, the auxiliary fan will behave the same as the CPU's fan. But if I disconnect the PSU to the motherboard and trick it to run using a paperclip, the auxiliary fan runs normally.

Everything leads me to think the problem is the motherboard. But you guys probably have more experience in this than I do.

This really narrows down, eliminating a failed CPU too, the issue to 2 things. First it could be the MB, but lets go with one more test.

Remove the MB connection to your cases power and reset buttons and any other cables there, including speaker (if there) and any lights (prolly just HDD). Ideally would be to have a spare power button and cable to use here, or if the board has a power on button built onto it. Having neither, just plug your case power button back in, I dont suggest jumping it what anything else as you could short something else out. This will eliminate switches or accidental grounding. This also assumes your PSU is in perfect working-as-intended order.

Okay, done that; Removed the plug and put it back in and also removed every other connection like you asked. I don't have a different case or a builtin power button.. Same problem persists. Also I recall when the problem first started the computer froze completely. After that initial crash it just stopped working, so I don't think it was a problem with the power switch.

So, do you think it's the MB? Just to recape
-PSU works on another machine.
-Exchanging PSU doesn't give me different results.
-While breadboarding I got the CPU fan to run normally once, but I had no RAM installed.
-Cleaned the machine.

 

[Yamitime]

take out the CPU and ram and try to power it, but leave the CPU fans connected.

All right I've done that. I got the same issue. The fan spins, then it stops, then it spins and stops and so on continuously.

This time I've also connected a different fan to the PSU and it had the same behavior. But that's just when the PSU's 24 pin connector is hooked to the mobo.

However, if I trick the PSU to start using a paperclip, the fan connected to the PSU runs nicely.

Spoiler

I'm starting to think it's definitely the motherboard. This is not the first time a motherboard dies on me. I've had it happen 2 or 3 other times before. I used to think it was on account of cheap power supplies, but I'm starting to think it's the case or something. The case is the only component that's been the same throughout all the motherboard failures. I've once had a motherboard's capacitor blow.

So, summing up the discoveries so far:

My machine will behave the same regardless of the PSU I'm using.

My current PSU behaves normally on another machine.

I get the same behavior if the only thing hooked to the motherboard is the CPU fan.

If I connect the motherboard and the PSU and if I connect an auxiliary fan and the PSU, the auxiliary fan will behave the same as the CPU's fan. But if I disconnect the PSU to the motherboard and trick it to run using a paperclip, the auxiliary fan runs normally.

Everything leads me to think the problem is the motherboard. But you guys probably have more experience in this than I do.

This really narrows down, eliminating a failed CPU too, the issue to 2 things. First it could be the MB, but lets go with one more test.

Remove the MB connection to your cases power and reset buttons and any other cables there, including speaker (if there) and any lights (prolly just HDD). Ideally would be to have a spare power button and cable to use here, or if the board has a power on button built onto it. Having neither, just plug your case power button back in, I dont suggest jumping it what anything else as you could short something else out. This will eliminate switches or accidental grounding. This also assumes your PSU is in perfect working-as-intended order.

Okay, done that; Removed the plug and put it back in and also removed every other connection like you asked. I don't have a different case or a builtin power button.. Same problem persists. Also I recall when the problem first started the computer froze completely. After that initial crash it just stopped working, so I don't think it was a problem with the power switch.

So, do you think it's the MB? Just to recape
-PSU works on another machine.
-Exchanging PSU doesn't give me different results.
-While breadboarding I got the CPU fan to run normally once, but I had no RAM installed.
-Cleaned the machine.

Have you plugged the extra power connection to the MB 4pin(sometimes 8 pin) near the cpu .
1 x 4-pin ATX 12V Power connector

 

[Vicaris]

I took it to a maintenance guy and he confirmed that it was indeed the motherboard. I bought a new one.