PC trying to start, then turning off, on, off etc

Jonny Chee · 5 Jan 2013 at 16:59

Help!

I left my machine for an hour running Prime 95 on a new 4.6 GHz overclock and when I came back to it it was off. I thought it was just in sleep mode but when I turned it on, it fired up for a second or so, then turned off, then repeated the process until I turned off the power.

It was running Prime 95 for about 30 minutes before I went out and temperatures seemed pretty stable, peaking at around 70c.

My system is:

CPU: i5 2500k (Matterhorn Pure CPU Cooler)
GPU: HIS IceQ 7950 Boost (only a week old)
MOBO: Gigabyte Z68AP-D3
RAM: 8 GB Exceleram 1333mhz
PSU: Seasonic G Series Gold 550w (also only a week old)
CASE: Coolermaster HAF 912 Advanced (2 days old)

Any help or advice on what to try would be greatly appreciated.

snips86x · 5 Jan 2013 at 17:02

Can you find anything in event viewer?

tnx · 5 Jan 2013 at 17:04

Have you tried booting into the BIOS and resetting it to defaults.

Jonny Chee · 5 Jan 2013 at 17:05

snips86x said:
Can you find anything in event viewer?

It won't stay on for more than a second or two, wouldn't I need to be in Windows to see event viewer?

Jonny Chee · 5 Jan 2013 at 17:06

tnx said:
Have you tried booting into the BIOS and resetting it to defaults.

It literally turns itself straight off so I don't even think I could get that far. I tried resetting the CMOS by removing the battery but still the same.

G18241 · 5 Jan 2013 at 17:07

Jonny Chee said:
It literally turns itself straight off so I don't even think I could get that far. I tried resetting the CMOS by removing the battery but still the same.

My RAM died once and i had this problem...do you get any bleeps when it resets?

Jonny Chee · 5 Jan 2013 at 17:10

G18241 said:
My RAM died once and i had this problem...do you get any bleeps when it resets?

No bleeps, I push the button, get power for a second, then it cuts out. Then it just repeatedly starts and cuts out over and over again.

I don't think it's even on long enough to bleep.

tnx · 5 Jan 2013 at 17:11

That dont sound too good.

Have you got other parts to swap around to pin the problem down.
i.e. another chip on the same socket. RAM and graphics card.

I would swap and try different bits.

Hopefully somebody will have a better reply.

Hope it does get better for you

abbotsmike · 5 Jan 2013 at 18:28

I'd recommend stripping the system down as far as you can. I think a similar problem I had was caused by a graphics card, but it was a long time ago! Also had it caused by a faulty power supply in a server.

If the system will boot up without the graphics card and some of the RAM, then you might be able to pinpoint the problem.

Jonny Chee · 5 Jan 2013 at 18:29

Problem solved.

Reset the CMOS again (left battery out for longer this time).

Disconnected 24 pin from motherboard and drained all power by holding power button down for one minute (read that somewhere).

Powered up again and everything works. BIOS even had my 4.5GHz settings from where I saved them before.

Phew!

tnx · 5 Jan 2013 at 18:39

Jonny Chee said:
Problem solved.

Reset the CMOS again (left battery out for longer this time).

Disconnected 24 pin from motherboard and drained all power by holding power button down for one minute (read that somewhere).

Powered up again and everything works. BIOS even had my 4.5GHz settings from where I saved them before.

Phew!

ohhhhhhhhhhhhhhhhh bet you were worried then....

Nice one......

HUGE SYYYYYYYYYYYYYYYYYYYYYY

Jonny Chee · 15 Jan 2013 at 12:18

Very interesting. Had system running great for ages on a 4.5GHz overclock.

I try 4.6GHz again last night and all seemed fine in Prime and whilst gaming.

Turn the machine on this morning and the same thing happened again!

Power on, off, on, off every 2 seconds...