New build problems - troubleshooting fail

[Jordanp1]

Hey everyone, got another build problem. This one has a lot of people scratching their heads so I thought I'd bring it to you all for some extra help.
Here's the particulars:

MOBO: GIGABYTE GA-880GA-UD3H AM3 AMD 880G

Optical: SAMSUNG Black Blu-ray Drive SATA Model SH-B123L

OS: Windows 7 Home Premium 64-bit

CPU: AMD Phenom II X4 840 3.2GHz Socket AM3 95W

Memory: Patriot 2 x 4GB 240-Pin DDR3 1600 (PC3 12800)

PSU: CORSAIR Builder Series CX430 CMPSU-430CX 430W

GPU: ASUS EAH5670/DI/512MD5/V2 Radeon HD 5670 512MB 128-bit DDR5

HDD: HITACHI Deskstar 7K1000.C 1TB 7200 RPM SATA

WIFI Adapter: Rosewill RNX-G300LX IEEE 802.11b/g PCI Wireless Card


The short of it is, when we turn it on, we get lights and fans (including CPU fan) but no video output. There's neither output to the onboard video nor the graphics card.

We've done a lot of trouble shooting already so I'll give you the history of what we've tried so far:
First, we started with a different Mobo: (original) ASUS M4A79XTD EVO AM3 AMD 790X

We started by trying the monitor and cable on a laptop and that worked fine. The next thing we tried was building the stripped down PC outside the case and there was no improvement. We eventually realized that our board didn't support our particular model of CPU so we RMA'd it and got the Gigabyte board listed above.
Got the new board, plugged it in, everything's hooked up - still got the same problem: a black screen with a "no signal" message on the monitor.

The only idea I have left is that the PSU is too small, but every PSU calculator I used told me I needed only around 300W so I got the 430W to be safe. Do you have any other ideas or do I need to order a bigger PSU?

[glc]

Have you tried it out of the case with ONLY the basics?

PROBLEMS with a NEW BUILD? Try This!!

Your new mobo has onboard video - have you tried it with that? Onboard video, one stick of ram, out of the case.

FYI, when you do get it working, leave the wireless adapter out till you have Windows installed. The drivers need to be installed PRIOR to installing the card. With 64 bit Windows, you need to download the drivers, do not use the CD.

[Extremerc12]

Have you looked on the back side of the CPU, to see if any of the pins are missing? If the cpu you have listed is what you tried in the Asus M4A79TD then it was fine.

Have you tested with another power supply by chance? I have a machine sitting here right now with me that has the same symptoms. I switched out the psu and she fired right up.

Just to be clear, you are not seeing the initials screens correct? In other words, you cannot enter Bios or anything like that.

[rwest]

GIGABYTE GA-880GA-UD3H AM3 AMD 880G HDMI SATA 6Gb/s USB 3.0 ATX
From Newegg:

Max Memory supported: 16gb

Memory Standard
DDR3 1866(OC)/1333/1066
* To reach DDR3 1866MHz or above, you must install two memory modules and install them in the DDR3_3 and DDR3_4 memory sockets.

Hmmn, I wonder if you must install only two stix of memory in slots 3 & 4?