ATX Power supply question

[William W. Plummer]

I have a dead system -- LED and fans come on, but no beep, nothing on
monitor. Same with all PCI cards removed and everything unplugged from
mobo. I suspect the power supply. Can anyone verify that the voltages
below are correct for an ATX system. These were taken on the main mobo
power connector.

(0) 3.4 ORN ORN 3.4 (0)
(0)-12 BLU ORN 3.4 (0)
0 BLK BLK 0
(4.6) 0 GRN RED 5.1 (0)
0 BLK BLK 0
0 BLK RED 5.1 (0)
0 BLK BLK 0
(0)-4.9 WHT GRA 4.9 (0)
(0) 5.1 RED PRP 5.1
(0) 5.1 RED YEL 12.3 (0)

Number in parens () is with the power "off".
So, PuRPle must the the power for the on/off switch logic.
And, GReeN must be the command to the power supply to turn on.

Thanks for any advice.

 

[Gary Tait]

Whereas On Sun, 26 Oct 2003 01:33:46 GMT, "William W. Plummer"

I have a dead system -- LED and fans come on, but no beep, nothing on
monitor. Same with all PCI cards removed and everything unplugged from
mobo. I suspect the power supply. Can anyone verify that the voltages
below are correct for an ATX system. These were taken on the main mobo
power connector.

(0) 3.4 ORN ORN 3.4 (0)
(0)-12 BLU ORN 3.4 (0)
0 BLK BLK 0
(4.6) 0 GRN RED 5.1 (0)
0 BLK BLK 0
0 BLK RED 5.1 (0)
0 BLK BLK 0
(0)-4.9 WHT GRA 4.9 (0)
(0) 5.1 RED PRP 5.1
(0) 5.1 RED YEL 12.3 (0)

Close enough.

 

[w_tom]

Also Gray wire is power supply telling motherboard that it
has supplied good power. It is a good power supply. Move on
to other possible reason for failure.