Computer build immediately turns off

hughtrimble · 22 Mar 2014 at 16:54

Afternoon all,

Hope you are having a pleasant weekend.

I put together a build a few weeks back with help from this great forum, and it has been running flawlessly for that time. BF4 on ultra for hours at a time with the GPU and PSU at nice low temperatures etc (circa 75 deg c and 45 deg c respectively).

Having put my computer to sleep (accidentally, as when I leave it I prefer to turn it off fully, given how rapid it is to start-up), on my return after maybe 30mins to an hour, I pressed the front panel's power switch to switch it on again, and I got half a second or so of lights and fans. Then nothing. The mobo's power light was on though. Pressed the power switch a second time, and this time no fans or lights at all.

I unplugged it from the mains, waited for a few minutes (mobo's power light went off) and I plugged it back in, and pressed the front panel's power button:

- Half a second of lights (on the front panel's power button LED, PSU water cooler and mobo's 'numerical display')
- Half a second of fans (fans ran in the PSU, GPU, CPU's water-cooling radiator and all case fans; i.e. all the fans.)

I have tried to follow thegeneral troubleshooting guide, including the 'hotwire' test, which showed the PSU to power a fan just fine.

I have reset the CMOS too, and shorted the front panel's power button switch, which resulted in the exact same half-second of fans and lights as using the switch itself.

My build specs are:

Gigabyte Radeon R9 290 OC WindForce 4096MB

Gigabyte Z87X-UD4H Intel Z87

Intel Core i7-4770K 3.50GHz (Haswell)

Corsair Hydro H100i

Corsair Carbide 330R Silent Mid Tower Case

TeamGroup Vulcan ORANGE 8GB (2x4GB) DDR3

SuperFlower Golden Green HX 650W non-modular

Does anyone have any good ideas as to what I can try next?

I haven't yet managed to check if it's the reset button perhaps doing something iffy, as I can't find a way of disconnecting it.

Any ideas at all would be greatly appreciated.

Hugh

stulid · 22 Mar 2014 at 16:58

Pull the GFX card out and plug the monitor directly into the board.

Try one RAM stick at a time in the different slots.

hughtrimble · 22 Mar 2014 at 17:20

stulid said:
Pull the GFX card out and plug the monitor directly into the board.

Try one RAM stick at a time in the different slots.

Hi Stulid,

Just tried the RAM down to one stick, and then also switched the sticks - still just the half second of fans and lights.

Also first of all just unplugged the GPU from the PSU and the same half second of power occurred. Then totally removed it from the mobo, and the same half second of lights and fans again.

Cheers for the suggestions though!

wazza300 · 22 Mar 2014 at 17:25

you have onboard bios switch? flick it and boot from backup bios

also when clearing cmos its best to leave battery out a good 5 minutes due to the board still storing power ect

led clock should read A0 if successful boot

stulid · 22 Mar 2014 at 17:25

Unplug all drives and any USB stuff and so you literally have just CPU/Board a stick of RAM and the cooler.

Hotwired · 22 Mar 2014 at 17:39

hughtrimble said:
I have reset the CMOS too, and shorted the front panel's power button switch, which resulted in the exact same half-second of fans and lights as using the switch itself.

When you say shorted what do you mean you did?

The power button is a momentary switch, press once and its meant to start.

Holding it down and keeping the circuit closed causes it to power off shortly after turning on which might be relevant.

hughtrimble · 22 Mar 2014 at 17:56

wazza300 said:
you have onboard bios switch? flick it and boot from backup bios

also when clearing cmos its best to leave battery out a good 5 minutes due to the board still storing power ect

led clock should read A0 if successful boot

Just tried the bios switch - same as before with the momentary on.

I can't actually get the cmos battery out, it's just too fiddly, but the mobo has a cmos reset button, which I pressed. Same outcome.

LED clock reads this symbol, which flashes twice in the time it turns off in:

It's a screenshot of a video taken on my phone, hence the big 'play' symbol!

I can't find that symbol in the mobo's manual.

hughtrimble · 22 Mar 2014 at 17:57

Hotwired said:
When you say shorted what do you mean you did?

The power button is a momentary switch, press once and its meant to start.

Holding it down and keeping the circuit closed causes it to power off shortly after turning on which might be relevant.

I shorted it in the manner that was noted in the troubleshooting thread:

3. Front Panel Connections - Check that the front panel “Power On” cable is connected to the correct front-panel header on the motherboard. If you suspect a faulty switch or cable, then you can test this by “Shorting” the two pins with a flat head screw driver. If the PC starts with the screw driver but not with the front panel cable or switch then it would appear the front panel cable/switch is faulty. Likewise, check the “Reset” connector. If this is shorting, it can cause shutdown/restart problems.

It does turn on with the front panel button, but only for a moment.

Thank you for the suggestion though - I hadn't realised the power button was momentary only. Perhaps it's the power switch then?

wazza300 · 22 Mar 2014 at 17:58

what about bios switch? im not sure if that board has one or not

to get the battery out pinch the metal tangs and the battery lifts up,you can then get your fingernail under it and lift out

you can also swap the reset switch wires with the on/off button wires(and start pc with reset button) to rule out faulty power button switch

stulid · 22 Mar 2014 at 17:58

Never seen that before, a single digit, usually its chucking pairs at you.

stulid · 22 Mar 2014 at 17:59

If you live close then im prepared to start messing around exchanging parts if that an option.

hughtrimble · 22 Mar 2014 at 18:01

wazza300 said:
what about bios switch? im not sure if that board has one or not

to get the battery out pinch the metal tangs and the battery lifts up,you can then get your fingernail under it and lift out

you can also swap the rest switch wires with the on/off button wires to rule out faulty power button switch

Tried the bios switch (same outcome). I have tried the battery repeatedly! I just can't get my fingers under the sides with the tab depressed. But the board has an inbuilt cmos reset, so that should do the same I'dve thought.

How would I go about swapping the rest switch wires with the on/off button wires?

Thank you for the suggestions again Wazza

hughtrimble · 22 Mar 2014 at 18:03

stulid said:
Never seen that before, a single digit, usually its chucking pairs at you.

That doesn't sound good. Perhaps it's the mobo then?

stulid said:
If you live close then im prepared to start messing around exchanging parts if that an option.

That's very kind of you Stulid. I'm in London/Surrey, so rather far! But I very much appreciate the kind offer.

wazza300 · 22 Mar 2014 at 18:05

where they connect to the motherboard

reset and power just swap them over then power on the pc with the cases reset button

would be good to test with another psu even if it spins when shorted

long cmos clear would be good also,im not a fan of cmos switches

hughtrimble · 22 Mar 2014 at 18:08

stulid said:
Unplug all drives and any USB stuff and so you literally have just CPU/Board a stick of RAM and the cooler.

Just tried it - exactly the same as before unfortunately.

This is rapidly narrowing down the possible culprits!

stulid · 22 Mar 2014 at 18:18

Keep trying what wazza is suggesting, but,

Take everything out of the case and lay the board on a box or some card board etc.

That should then rule out any shorts from the case (even though its been working fine before)

hughtrimble · 22 Mar 2014 at 19:03

wazza300 said:
where they connect to the motherboard

reset and power just swap them over then power on the pc with the cases reset button

would be good to test with another psu even if it spins when shorted

long cmos clear would be good also,im not a fan of cmos switches

Ah I see, thank you.
Just switched them - exactly the same result.

But...finally got the mobo battery out, and left it for half an hour. Turned the system back on, and it powered up for around five seconds, powered itself off, and then powered itself back on again, and it's running.

Cancel my no screen output comment - my screen just didn't register it until I turned the screen on and off again

hughtrimble · 22 Mar 2014 at 19:07

stulid said:
Keep trying what wazza is suggesting, but,

Take everything out of the case and lay the board on a box or some card board etc.

That should then rule out any shorts from the case (even though its been working fine before)

Fortunately I didn't need to remove all the kit from the case - the long no cmos power seems to have sorted it, at least getting to the BIOS screen.

I'll reconnect components one by one and see if it occurs again.

On Holiday · 22 Mar 2014 at 19:07

Off topic question aimed at those who know;

Turned the system back on, and it powered up for around five seconds, powered itself off, and then powered itself back on again, and it's running.

My ASUS P9X79 Pro does this every time the power cable is removed from the system - is this normal?
Although it's probably: Push power button, powers up, 2 seconds later, powers down, 2 seconds later, powers up and runs.

wazza300 · 22 Mar 2014 at 19:52

YarwoodUK said:
Off topic question aimed at those who know;

My ASUS P9X79 Pro does this every time the power cable is removed from the system - is this normal?
Although it's probably: Push power button, powers up, 2 seconds later, powers down, 2 seconds later, powers up and runs.

i think someone turned off cpu pll overvoltage and cured it,was on asus z77 though

if your removing cables then it can sometimes upset the startup/detection