PC boots up then shuts down, no signal, repeats cycle

[AdamAnubis]

Right, help urgently needed here.

I was going to plug the fan into a fan controller I had, so did that, booted up, and there was no signal going to the monitor, but all fans were spinning. Thinking it was the fan controller, I unplugged it, same issue happened. Unplugged the fan, same issue happened.

As far as I am aware the controller isn't plugged into anything else. It's something I put in but never bothered connecting up.

The PC boots up for about 30 seconds, then shuts down for a few seconds...then everything starts going again.

Any ideas? From what I can see nothing's unplugged nor did I knock anything.

[TAKTAK]

reseat the power connectors, p4 and main 24pin. Then reseat the gfx card and pcie power connectors too.

[AdamAnubis]

Done both, basically reconnected all of the power connectors and tried my old card as well.

Only thoughts on what it could be is a dead CPU or CMOS battery doing something wrong?

[AdamAnubis]

The problem started when I connected a Fan Controller to it (just a Molex and connects to the fan) to try and alter the 2000RPM fan at the back. As far as I can see it's not connected to anything else in the PC. I didn't manage to change the speed on the fan as I was busy trying to deslect the clock (the FC uses a LED display and has a little clock on it) to try and change the fanspeed when I realised that the montiors were recieving no signal, and the PC then shut down after 30 seconds or so.

[AdamAnubis]

Could it be the CPU? I have a E8400 @3.0GHz but recently I'd noticed on a Vista sidebar (tracks the CPU Usage) that it was reading at 2667MhZ (or something like that). Equally on the system in control panel it said E8400 Dual core 3.0Ghz and 2.4Ghz.

I assumed this was some form of my motherboard power saving thing where it underclocks it to save power, but not sure. I have nothing to compare it to though so not hugely sure if it's always been like this.

[GoNz0]

its rare a cpu will go under normal use, its clocking back using speedstep so thats normal.

looks like you may have a fried psu ?

[AdamAnubis]

Thought that, there's no visible signs of it doing so though, plus is a corsair so I'd have thought it'd be pretty sturd and isn't exactly under high strain atm.

[AdamAnubis]

Would it be worth me taking out the RAM and seeing if it beeps or something? I'm not sure if the PSU fan is spinning (not checked/didn't think about it). On the motherboard all the lights are green (gigabyte mobo) so that looks normal. Though I can't remember if my PC beeps when it starts up (I usually hit on and then leave the room) or not so can't compare this with what's normal.

[AdamAnubis]

Crisis over....i think :s It's working agian. I didn't do anything beyond resit the RAM so that must have been it...but I dunno. Thank you anyway for your help

[Reefer86]

when ever a cpu has died on me the pc wont boot at all, i would surgest a bad connection or psu and im leaning more to a psu fault.

[TAKTAK]

Glad you got it sorted

Sorry i couldn't be of more help, i was walkabout posting from my phone

[AdamAnubis]

Glad you got it sorted

Sorry i couldn't be of more help, i was walkabout posting from my phone

Ahh Explains a lot. Thanks, yeah, it was annoying as it didn't work then just...did