Computer turns on for a split second then turns off, having difficulty finding the root of the issue

[gyogyomega]

Hello, I've gone around doing some research on other old threads about this issue but have had no success. My computer turns on briefly then turns off in about half a second. I get no beeps whatsoever from the motherboard, just the system turns on super briefly and the fans turn on, but then it shuts down. I also made sure I'm not tripping the circuit breaker in my wall socket. I'm having difficulty narrowing down the possible causes but have gone through a few already. My specs are:

-Gigabyte z97m-d3sh which supports 2400 RAM motherboard

-Ripjaw 2400 240 pin RAM (2 sticks, 8gb each)

-i5 4690k processor

-EVGA GTX 970

-Rosewill 700W power supply

-thermal take CPU fan that supports the i5 4690k

-one old 3.5 HDD and a SSD, both having all the drivers uninstalled on them. I also tried a blank hard drive

-2 system fans

Things I've already trouble shooted:

-My power supply is not the issue, I'm getting the correct amount of volts and have actually tried other power supplies with the computer. The same issue occurred. I don't think it's my 700W supply. I did check that the 2x4 pin CPU power plugs were in tight, and the motherboard powersupply was in too. My CPU fan was also plugged in. And I have flipped the power switch on the PSU and made sure it was not tripping the socket.

-My motherboard is not shorting to the case. I have standoffs installed and made sure it's not touching the case at all

-Took out RAM one at a time to see if that was causing the issue

-removed the graphics card completely to see if the computer would at least start up without it

-made sure I have the right power cables plugged into the right devices, I have thoroughly read the manuals for my CPU, GPU, and motherboard

-used blank hard drives and hard drives that have all the drivers uninstalled on them, not sure if this would affect the boot up but I tried it anyway

Another thing that I'm concerned about is my CPU. I just barely touched the processor chip's underside, which I know I'm not supposed to touch. Also, some thermal paste was sort of on the edge of that chip. Maybe the CPU fan's underbracket is touching the case? I'm not sure.

Please help!

 

[alexoiu]

Hi, I suggest testing the board outside the case. See if still same issue.

 

[gyogyomega]

Hi, I suggest testing the board outside the case. See if still same issue.

I'll try that

 

[Bob57]

Could also try resetting the CMOS. I've seen crashes like that where the CMOS settings had junk in it and needed a reset.

 

[gyogyomega]

Hi, I suggest testing the board outside the case. See if still same issue.

I took the motherboard out and tried it, still turned on for half a second. At least that's one thing we know it's not!

Could also try resetting the CMOS. I've seen crashes like that where the CMOS settings had junk in it and needed a reset.

So to reset it, I take out the round silver battery and after 5 minutes, put it back in and try turning it on? I'll try it now

 

[alexoiu]

"I took the motherboard out and tried it, still turned on for half a second. At least that's one thing we know it's not!'
After resetting the CMOS, if still same issue, try removing the 4 (or 8) pin power cable from motherboard (leave only the 24 pin one), connect a case fan to the board and start it. See if the case fan does spin

 

[gyogyomega]

"I took the motherboard out and tried it, still turned on for half a second. At least that's one thing we know it's not!'
After resetting the CMOS, if still same issue, try removing the 4 (or 8) pin power cable from motherboard (leave only the 24 pin one), connect a case fan to the board and start it. See if the case fan does spin

I removed the 8 pin CPU power supply after leaving the CMOS battery out for 5 minutes and replacing it. The fans still turned on, but the computer only ran for half a second again.

I should also mention that nothing is plugged into my system fan 4 pin connector on my motherboard. My case came with two case fans that connect via 1 adapter to a molex 4 pin power cord

The fans for everything still turned on, though. Do you want me to take out my processor and check for damage?

 

[alexoiu]

No. If board outside the case and power supply working then it looks like a board issue. I suggest RMA-ing it.

 

[gyogyomega]

No. If board outside the case and power supply working then it looks like a board issue. I suggest RMA-ing it.

I might have too. Still though, I took out my CPU and found thermal paste going over the sides of my CPU chip. I'l try cleaning it with alcohol, and also testing if the CPU itself is fried. I imagine a CPU not working would prevent boot up, would I be correct?

 

[alexoiu]

The 8 pin cable out excluded the CPU from the equation. The case fan (if connected to a case fan header) should spin without stopping when board started.

 

[gyogyomega]

The 8 pin cable out excluded the CPU from the equation. The case fan (if connected to a case fan header) should spin without stopping when board started.

First of all, thank you for being so patient and helpful!

I tested the power supply by using a paper clip in the 24 pin motherboard power supply. All the fans turned on and stayed on that way. So if the CPU is out of the equation, and doesn't affect the bootup of the fans and everything else, then something with my motherboard is to blame? I can return my current one and get a new one, but again I imagine the reasons for the motherboard not turning on are plentiful. The power supply could be working but the motherboard could not be working somewhere else. Thank you for your help thus far!

 

[alexoiu]

You're welcome.
I'd say to RMA the board.

 

[Ozgeopc]

Hello, I've gone around doing some research on other old threads about this issue but have had no success. My computer turns on briefly then turns off in about half a second. I get no beeps whatsoever from the motherboard, just the system turns on super briefly and the fans turn on, but then it shuts down. I also made sure I'm not tripping the circuit breaker in my wall socket. I'm having difficulty narrowing down the possible causes but have gone through a few already. My specs are:


Please help!

OK based on another topic where StarTech57 suggested permanently bridging pins 15 & 16 on the 24-pin plug I tried a variation by soldering a momentary make single pole push button to the two leads (green and black) connecting to these two pins via a short bit of twin flex. Then to my surprise after booting by holding this button made, rather then the normal start button my PC burst back into life and now after several normal shutdowns the PC boots by using the normal start button. I did have to set BIOS again only to give the correct boot sequence.

You may have to try this a few times, which was the case for me but then it worked.

This shows that there is something that gets confused on the mobo or PSU and this workaround may solve the problem. Or at least until it ever happens again, then I have the push button switch ready to do its trick again. Because so many people have this symptom there may well be a design bug that this works around. Note: this will only be a fix if there is not a real problem that this sensing is supported to catch.

I hope this may help others. Cheers Anton