Keeps Switching on and off for 1/2 second intervals.. please any help!? could be mobo

[juicyrooter]

Hi,
Ok so my previous problem of it crashing once your in windows and occasionally outside (found here http://www.computerforum.com/59919-screen-keeps-coming-up-no-input-when-there-input-might-psu.html)
has got worse..

Now when you press the power switch, it turns on. 2 seconds later-ish , it turns off, turns on.. turns off turns on.. you get the idea.
Nothing ever comes on the screen, but that is quite likely just because as you know screens take a few seconds to display an image and the computer is turning on and off faster than that.

I immediately offcourse thought it could be the Psu, but after putting my own 90 pounds decent Psu in there, and it did the exact same thing, I think it may be the mobo, but offcouse am not 100% but I am going to post it on the mobo section of the site aswell.

Could be static?

Well I took the mobo, the graphics and cpu/ram/psu out of the case and built it, and it still did the same, surely thats a good test?

So what do you think people?

I really appreciate you computer forum people helping me, this is the most uber computer I built (except it not working lol) and I really want it to work as you can imagine!

Many thanks!
Rob.

This is the computer:

Clabs Inspire 5800 5.1 Speakrs

Gbyte 965P-S3 s775 Conroe

Intel E6400 Core2Duo 2.13GHz

1G DDR2 667 PC5300 CL5

1G DDR2 667 PC5300 CL5

KEYSONIC USB/PS2 LASER MOUSE

SC EZ8810 BLACK MM KEYBOARD

Terratec Aureon 5.1 PCI SCard

Sony DWQ120AB Black DVDRW

19 V7 L19WA WIDE SCREEN

160G Samsung PATA 7200/8

256MB Leadtek 7900GT PCI-E

Sstone Silver TJ01S TemJin Cas

 

[Cromewell]

Try changing the RAM with some cheap stuff. That sounds like the gigabyte 'I don't like RAM' boot loop

 

[StrangleHold]

If you have the case speaker hooked up does it make any beeps when it first boots?

 

[Garyj881]

You could take out the ram and just see if you can get in bios

 

[ceewi1]

I have moved this thread to the Desktop Computer section, where I feel it is better suited. Please try not to post multiple threads on the same topic.

I would firstly recommend resetting the CMOS, if you haven't already.

You could take out the ram and just see if you can get in bios

You can't post without RAM... If you have another RAM chip lying around that is confirmed to work at 1.8V, it would be worth trying it, though.

 

[toddl1]

have you got a system speaker plugged in?
because if you dont you be missing beeps. beeps sometimes mean
"Im overheating, Im microsoft, i like to beep"

overheating an startup problems can be closely related, sometimes bad wiring can do that.

 

[Archangel]

overheating an startup problems can be closely related, sometimes bad wiring can do that.

you know that if bad wire-ing is causing heat issues, youre putting a few amp's through something where its not supposed to be, right?