14-pin Compaq ATX to 20-pin mobo

[Jaz]

I want to use a Compaq 14-pin ATX power supply from a Deskpro 4000EN
on a normal 20-pin ATX motherboard (I know this sounds silly, but I
have two other 4000en's running Linux and Solaris, and this 90W PSU is
extremely quiet, so this case/PSU would make i nice home for my
mini-ITX allways-on system, which only needs 50Wor so)

So if this isn't a totally rediculous idea, then how would I wire the
14-pin PSU to 20-pin mobo?

PSU System board

1 +3.3Vdc 1 +3.3Vdc
2 +3.3V Sense 2 +3.3Vdc
3 Signal GND 3 Signal GND
4 +5Vdc 4 +5Vdc
5 Signal GND 5 Signal GND
6 +5Vdc 6 +5Vdc
7 Signal GND 7 Signal GND
8 +3.3Vdc 8 PWR-OK
9 -12Vdc 9 +5VSB
10 Fan Off 10 +12Vdc
11 On/STBY 11 +3.3Vdc / 3.3V Sense
12 +5V Aux 12 -12Vdc
13 +3.3V Sense 13 Signal GND
14 +12Vdc 14 PS-ON
15 Signal GND
16 Signal GND
17 Signal GND
18 -5Vdc
19 +5Vdc
20 +5Vdc

Thanks

 

[Gary Tait]

I want to use a Compaq 14-pin ATX power supply from a Deskpro 4000EN
on a normal 20-pin ATX motherboard (I know this sounds silly, but I
have two other 4000en's running Linux and Solaris, and this 90W PSU is
extremely quiet, so this case/PSU would make i nice home for my
mini-ITX allways-on system, which only needs 50Wor so)

So if this isn't a totally rediculous idea, then how would I wire the
14-pin PSU to 20-pin mobo?

PSU System board

1 +3.3Vdc 1 +3.3Vdc
2 +3.3V Sense 2 +3.3Vdc
3 Signal GND 3 Signal GND
4 +5Vdc 4 +5Vdc
5 Signal GND 5 Signal GND
6 +5Vdc 6 +5Vdc
7 Signal GND 7 Signal GND
8 +3.3Vdc 8 PWR-OK
9 -12Vdc 9 +5VSB
10 Fan Off 10 +12Vdc
11 On/STBY 11 +3.3Vdc / 3.3V Sense
12 +5V Aux 12 -12Vdc
13 +3.3V Sense 13 Signal GND
14 +12Vdc 14 PS-ON
15 Signal GND
16 Signal GND
17 Signal GND
18 -5Vdc
19 +5Vdc
20 +5Vdc

Thanks

Personally, I'd snip off the plug from a blown supply, and connect
that to the appropriate wires form the good supply.

 

[Jaz]

Personally, I'd snip off the plug from a blown supply, and connect
that to the appropriate wires form the good supply.

Actually, it's the 14-pin PSU that I want to use -- it's not that this
power supply is blown, but that it's integrated into the case. So I'd
like to try to use it with a new 20-pin motherboard. I even have an
older standard 20-pin mobo that I can use as a test bed to make sure
the conversion isn't going to fry the new mobo (not right off the bat
anyway)
-jaz-

(Please excuse the 'burp' when replying)

 

[Gary Tait]

Gary Tait <[email protected]> forgot to take the pills and
typed:

Actually, it's the 14-pin PSU that I want to use -- it's not that this
power supply is blown, but that it's integrated into the case. So I'd
like to try to use it with a new 20-pin motherboard. I even have an
older standard 20-pin mobo that I can use as a test bed to make sure
the conversion isn't going to fry the new mobo (not right off the bat
anyway)
-jaz-

(Please excuse the 'burp' when replying)

Thats hwat I sad, tak the connector from a blown supply, and splice it
on the wires of the good supply. It doesn't matter which supply is
which, just that you jet the proper wire function on the proper wire.

 

[Spajky]

I want to use a Compaq 14-pin ATX power supply from a Deskpro 4000EN
on a normal 20-pin ATX motherboard (I know this sounds silly, but I
have two other 4000en's running Linux and Solaris, and this 90W PSU is
extremely quiet, so this case/PSU would make i nice home for my
mini-ITX allways-on system, which only needs 50Wor so)

So if this isn't a totally rediculous idea, then how would I wire the
14-pin PSU to 20-pin mobo?

PSU System board

1 +3.3Vdc 1 +3.3Vdc
2 +3.3V Sense 2 +3.3Vdc
3 Signal GND 3 Signal GND
4 +5Vdc 4 +5Vdc
5 Signal GND 5 Signal GND
6 +5Vdc 6 +5Vdc
7 Signal GND 7 Signal GND
8 +3.3Vdc 8 PWR-OK
9 -12Vdc 9 +5VSB
10 Fan Off 10 +12Vdc
11 On/STBY 11 +3.3Vdc / 3.3V Sense
12 +5V Aux 12 -12Vdc
13 +3.3V Sense 13 Signal GND
14 +12Vdc 14 PS-ON
15 Signal GND
16 Signal GND
17 Signal GND
18 -5Vdc
19 +5Vdc
20 +5Vdc

Thanks

You have a problem: you will need to generate additionally as I see:
-5 & -12V source ; IMHO not worth the trouble & problems realising
that; these days even small & quiet PSU are available @ reasonable
prices ....

-- Regards, SPAJKY
& visit site - http://www.spajky.vze.com
Celly-III OC-ed,"Tualatin on BX-Slot1-MoBo!"
E-mail AntiSpam: remove ##

 

[Jaz]

You have a problem: you will need to generate additionally as I see:
-5 & -12V source ; IMHO not worth the trouble & problems realising
that; these days even small & quiet PSU are available @ reasonable
prices ....

Ahhh, I missed that I didn't have a -5v source on the psu. Oh well.
thanx
-jaz-
(Please excuse the 'burp' when replying)

 

[ric]

Ahhh, I missed that I didn't have a -5v source on the psu. Oh well.

The need for a -5v supply has been removed from the ATX specifications.
The uATX spec never did have it. Whether or not *you* need it depends
on the MB you are using.

 

[Jaz]

The need for a -5v supply has been removed from the ATX specifications.
The uATX spec never did have it. Whether or not *you* need it depends
on the MB you are using.

I have the book on this motherboard (Jetway 614DF / B614DF) and it
shows a standard 20-pin ATX layout, just like the generic diagram I
used in my earlier post.

I'm still unclear if the multiple +3V and +5V supplies come from the
same sources/rails in the PSU -- but I guess I could rip apart an old
psu and inspect it. Pins 1-7 match on both, but what concerned me was
the lack of a 'PWR-OK' (ATX pin 8) and the soft logic +5v (ATX pin 9)
-- tho this might be the '+5v AUX' on the compaq psu. 20-pin ATX 15-20
I imagine are again individual rails.

As far as cheap supplies go -- well, I'll just say that if my finances
weren't the way they are then I would buy a shiny new mini-ITX case.
But I suppose $15 wont break the bank.

(Please excuse the 'burp' when replying)

 

[Gary Tait]

I have the book on this motherboard (Jetway 614DF / B614DF) and it
shows a standard 20-pin ATX layout, just like the generic diagram I
used in my earlier post.

I'm still unclear if the multiple +3V and +5V supplies come from the
same sources/rails in the PSU -- but I guess I could rip apart an old
psu and inspect it

They come from the same place, but use more wires to deliver more
current to the Mobo.

Pins 1-7 match on both, but what concerned me was
the lack of a 'PWR-OK' (ATX pin 8) and the soft logic +5v (ATX pin 9)
-- tho this might be the '+5v AUX' on the compaq psu. 20-pin ATX 15-20
I imagine are again individual rails.

For the PWR OK, I'd just pull that to +5V.

You could check to see if it works.

 

[ric]

I have the book on this motherboard (Jetway 614DF / B614DF) and it
shows a standard 20-pin ATX layout, just like the generic diagram I
used in my earlier post.

The fact that it uses a 20 pin ATX connector is unrelated to its need for
a -5v rail. What does the manual say?

I'm still unclear if the multiple +3V and +5V supplies come from the
same sources/rails in the PSU -- but I guess I could rip apart an old
psu and inspect it.

Yes, they do. All wires in that connector that are the same color come
from the same place.

the lack of a 'PWR-OK' (ATX pin 8) and the soft logic +5v (ATX pin 9)
-- tho this might be the '+5v AUX' on the compaq psu.

Your MB might require a "Power OK" (Power Good) signal to boot. The ATX
spec also details the timing of this signal. Page 17. Section 3.3 Figure 2.

http://www.formfactors.org/developer\specs\ATX_ATX12V_PS_1_1.pdf

 

[Jaz]

The fact that it uses a 20 pin ATX connector is unrelated to its need for
a -5v rail. What does the manual say?

Just a diagram showing the typical ATX signals, nothing about not
needing the -5V.

So I guess that old 14-pin supply is a 'uATX'? Well, I guess this one
will have to sit on deck for my other two 4000N's

Yes, they do. All wires in that connector that are the same color come
from the same place.


Your MB might require a "Power OK" (Power Good) signal to boot. The ATX
spec also details the timing of this signal. Page 17. Section 3.3 Figure 2.

http://www.formfactors.org/developer\specs\ATX_ATX12V_PS_1_1.pdf

Thanks for that link. It brings into perspective that saving $10-15 on
a psu isn't worth the risk of frying a $65 mobo, $40 memory, $50 cpu,
etc...
-jaz-
(Please excuse the 'burp' when replying)