motherboard/power supply incompatibility?

notme_at_oryou.com
Date: 08/17/04 

Date: 16 Aug 2004 23:27:48 -0500

I spent the day building a new system and it doesn't work. Here's the
specifics.

Motherboard: Tyan S2668ANR
Case Antec: Plusview 1000
power supply: Mercury EPS 12V (SSI) 550W

Before the packages arrived I spent the last week reviewing any
online documentation I could get my hands on regarding the chosen
motherboard, the Xeon processors, and power supplies.

When the packages arrived I did the following:

1) spent an hour reviewing the hardware manuals (which I had
already read online)
2) followed anti-static protocols to the letter!
3) installed EPS power supply in case and organized power bundles
4) took out mobo and inspected it for damage
5) laid mobo out on the antistatic mat and installed CPUs and
their respective thermal solutions.
6) noted that the intel addendum recommended against fan plugins
that use a tachometer feedback so I plugged the fans into
fan plugs on the mobo that had no feedback.
7) installed DDR memory (all four slots)
8) installed additional brass mobo standoffs (total of 10)
and installed mobo in case using metal screws provided (assumed
that if standoff screwholes attached to PCB traces then those traces
would be at case ground)
9) installed front panel indicator and switch leads to correct plug
on mobo (keeping mindful of common and +5 where LEDs are driven)
10) installed AGP graphics card (except supplemental power lead)
11) attached EPS 24 pin and 8 pin power plugs to mobo
12) installed pinnacle video capture card in unused PCI slot
13) installed three hard disks, one floppy drive, and a DVD/RW
unit in case (didn't connect power or data leads)
14) installed and attached supplemental case fans (case fans are
not supplied powered by mobo, but use +5/+12 plug splitters)
15) attached data cables and power leads to all drives and AGP card
16) reviewed cabling and power connections to make sure all were secure
17) attached VGA, keyboard, and mouse

Here's where it gets weird. When I plugged the power supply into the
wall outlet ALL fans spun briefly and post code LEDS lit up with FF
(all for about 1/2 second) then everything went dead.

I then unplugged the power supply and plugged it back in. Again, about
1/2 second of activity.

I then used the front panel power button and the machine DID power up.
I entered BIOS setup briefly then booted to linux so that I could do a
PCI bus scan. The PCI bus scan showed all applicable hadware to be
present. I did have a couple of cabling issues with the floppy drive
(plugged floppy in B plug instead of A) and had my DVD incorrectly
identified as a slave on a dedicated IDE channel.

I powered down the machine using the shutdown command then the front
power button. I then unplugged the machine from the wall and fixed
the cabling issues.

Now, regardless of what I do I cannot get the machine to power back up,
other than the 1/2 second fan spin when I plug in the power supply
and hit the power button. Post code flashes FF.

I then went back to a base level system with just the mobo to see if
the problem was due to overdrawing current on startup. Even when just
the mobo is installed the machine still exhibits this behavior.

Any suggestions as to what might be causing this? Is my power supply
bad, incompatible with the mobo, or is the mobo toast?

The mobo says it supports both EPS12V and ATX12V power supplies. Is
anyone confident that my getting an ATX12 supply will solve this?