computer won't boot, LEDs flash when power cord is attatched.

[Correction]

Just rebuilt my machine with a lot of new parts:

Antec 1200 case
gigabyte x48-ds4
radeon hd 4870 x2
zalman 850 watt power supply

the barracuda 1tb HDD wasn't found by windows or the BIOS when it first booted up, but otherwise the machine performed flawlessly once all the drivers for everything else were installed. I thought maybe I'd made a mistake in the placement of the jumpers/SATA cables so I opened it up again this morning, moved the cables (and only the cables) around and when I put the power cord back in all the LEDs in the machine began to flash. This includes the irritating LEDs on the Antec case fans, the LEDs on the graphics card and the LEDs on the motherboard. They flash once every three seconds and continue to do so for six seconds after I unplug the power cord. Antec's and Gigabyte's documentation on this behavior is...nonexistent and my current theory is that one of the parts doesn't like that I changed the hardware around after the initial build as some sort of retarded system intrusion lockout. However, putting everything back the way it was and closing the case didn't solve the problem.

HALP BG.

[Cephius]

It sounds like there is a short somewhere... make sure the motherboard is not making contact with the case anywhere. Maybe you nudged something when plugging the hard drive back in? As much of a pain as it'll be, I'd take everything out, put things back in one at a time and see if you still get the same results.

[Correction]

Well I reseated the video card and all the power connections and now nothing blinks, the red LED behind the power supply stays lit and the system won't start at all.

Hooray for sliding backwards!

[Correction]

Did a complete system recabling and it seems to have worked out. Thanks Cephius. I'm never buying another Zalman PSU. I suspect the 10x2 + 2x2 main motherboard power cable had uncoupled, leading the little 2x2 bit out enough to cause the short.

Edit: HAHA it still can't find my new HDD. Oh well, that's a problem I'll try to solve later.