Subject: Replace AS200 power supply with ATX?
To: None <port-alpha@netbsd.org>
From: Emil Skoeldberg <emil.skoldberg@nuigalway.ie>
List: port-alpha
Date: 10/25/2007 17:23:54
Hi,
I have an Alphastation 200 on which the power supply (seems to have)
died. From various sources on the web [1,2] it seems like it would
work to replace it by a standard off the shelf ATX power supply. This
would be straightforward if it was not for the fact that the connector
is not the same, so a bit of cutting and joining wires seems to be
needed.
My problem is that I do not fully see how this should be done.
(Electronics and hardware are not my strong points)
From [3] I got the pinout for ATX power supplys:
1 3.3V Orange +3.3 VDC
2 3.3V Orange +3.3 VDC
3 COM Black Ground
4 5V Red +5 VDC
5 COM Black Ground
6 5V Red +5 VDC
7 COM Black Ground
8 PWR_OK Gray Power Ok
9 5VSB Purple +5 VDC Standby Voltage (max 10mA)
10 12V Yellow +12 VDC
11 3.3V Orange +3.3 VDC
12 -12V Blue -12 VDC
13 COM Black Ground
14 /PS_ON Green Power Supply On (active low).
15 COM Black Ground
16 COM Black Ground
17 COM Black Ground
18 -5V White -5 VDC
19 5V Red +5 VDC
20 5V Red +5 VDC
And from the technical information for the alphastation, [4], I got
the pinout for the AS:
J19 J20
============================================
Voltage Pin Voltage Pin
Open 1 Ground 1
VDD 2 Ground 2
+12V 3 Ground 3
-12V 4 +3.3V 4
Ground 5 +3.3V 5
Ground 6 +3.3V 6
Ground 7 +3.3V 7
Ground 8 +3.3V 8
-5V 9 +3.3V 9
VDD 10 Ground 10
VDD 11 Ground 11
VDD 12 Ground 12
So to me it looks like a bit of a mismatch:
- more ground cables for the AS (is it Ok to split or join here?)
- same question for the +3.3V
- and what about Pin 1 on J19 (open, what does that mean?)
- what is "VDD"?
Any help would be greatly appreciated!
Emil
[1] http://osdir.com/ml/debian.ports.alpha/2003-08/msg00047.html
[2] http://www.webservertalk.com/message1250707.html
[3] http://pinouts.ru/Power/atxpower_pinout.shtml
[4] http://farrer.net/~rbf/files/docs/Alpha/ek-pcdsa-ti.pdf