PC turns on, then off after a second

[ivangs]

Hello,

I am new to these forums and have tried advice from previous threads with no luck.

My custom built gaming machine now does not turn on, It powers on for 1 second then turns itself off... If I leave it off for a while it lasts a fraction longer before dying.

Before I continue here are my specs -

MSI P7n Diamond
Intel Q6600 2.4ghz
Corsair xms2-6400 - 8GB total (tried using alternate sticks on their own)
ATI Radeon HD 5870
Silverpower Sp-s850

Currently everything is out of the case - literally the motherboard, cpu & heatsync, ram and PSU.... So nothing else except the essentials.

Using mobo PWR switch - it turns on then off...... If I put the Silverpower psu into an old motherboard it turns on fine....

If I put an old dell 350w psu onto my motherboard it turns of fine.

So both motherboards and psu's work fine in different systems..

Things I have tried;

Different ram sticks and different slots.
With or without gpu
With or without the 4 pin part on the end of the thick mobo power cable (what's that cable called ?)
with or without the 6 pin cpu power.
Removed CMOS battery
Cleared the cmos - no overclocking done.

It has been working perfectly with no issues at all, well stressed by battlefield 3 recently and in general a great machine.


I will take it to work and try a new psu with the mobo - and the psu in another machine.

I would really appreciate any help you can give,

Kind regards,

Ivan G-S

 

[Tmagic650]

"If I put an old dell 350w psu onto my motherboard it turns of fine"... Do you mean turns off or on?

This is definitely a power supply issue. It's an expensive motherboard so you need a great power supply that is at least 700 watts with SLI support

 

[ivangs]

Hello,

Thanks for your message... even though I read it back through I must have missed that - thanks for correcting me.

Well, it turns out it was the psu, because last night it blew up quite dramatically. So luckily it was not such and expensive replacement... still about 100 quid,,

After reading a lot of reviews and looking at lists of best PSU's from the experts

Source:

eggxpert.com/forums/thread/323050.aspx

I purchased the Corsair TX850w - so that will arrive on Friday..

Thanks anyway, your diagnosis is correct.

Ivan

 

[DarkDezire]

I know this sounds a little harsh but I was having the same issues about 1/2 hour ago I have a pretty decent gaming machine its not even a month old so after reading this site and a few others I was just a little angry ... but anyways heres how I fixed it ..... Unplug the mouse and keyboard all all that stuff including the power supply take tower to clear bench on the side of the motherboard (case still on) I gave 3 decent taps 1 up near the power button one about mid way and one by the back of the computer. After doing this I plugged power back in and turned on .... No Worries plug everything back in then get back to WoW ...
as I said it sounds a little bit harsh but I wasnt hitting the computer hard and from what I have seen on this forum and a few others ppl are saying everything from motherboard to powersupply or CPU hey I fixed mine without even taking the case off