andy wrote:
On Tue, 29 Sep 2009 06:07:48 -0700, Jonathan Sachs
wrote:

The MB is an EP45-UD3R. The subject line says everything else.

The manual tells me, "Do not insert the power supply cables into pins
under the protective covers when using a power supply providing a 2x2
12V connector." But the board came with no covers on any of the pins.

The connector is physically keyed, so it can only be plugged in one
way. The manual also tells you which pins are for 2x4 connector only.

http://www.playtool.com/pages/psuconnectors/eps.jpg

- 2x2 -
__ __ __ __
| | /b \ /c \ | |
|__| |__| |__| |__|
__ __ __ __
/a \ | | | | /d \
|__| |__| |__| |__|

latch

The four angled pins (a-d), prevent rotation and incorrect
insertion of the connector. The latch feature, should help
guide the proper compass point for insert.

This picture shows the final result. I tried to draw
my picture, to sorta match this.

http://www.playtool.com/pages/psuconnectors/4pinin8.jpg

(More connector info on this page. Worth a read.)

http://www.playtool.com/pages/psucon...onnectors.html

If the documentation is any good, it should mark four
pins on one (long) side as being +12V. The yellow wires on the
power supply connector should match up with those pins. That
would be a consistency check for correctness. Stop, if
the yellow wires aren't on the 12V side.

The diagram in the manual has numbers on it. An adjacent table
identifies the pins for usage with a 2x2. They'd be 3,4,7,8.
I'd probably have used a different notation, such as putting
text next to 3,4,7,8 saying "stick 2x2 here". In any case, the
keying feature should guide the insertion, and then the
results can be compared to the table, just to be sure.

1 GND (Only for 2x4 pin 12V)
2 GND (Only for 2x4 pin 12V)
3 GND ---
4 GND ---
5 +12V (Only for 2x4 pin 12V)
6 +12V (Only for 2x4 pin 12V)
7 +12V ---
8 +12V ---

HTH,
Paul