help ! pc psu compaq not working, trying to make bench tester

[Mavrick]

Hi all

do hope somebody can help me out here !

I had an old compaq deskpro that was working but now replaced and
needed a 12v 2 amp supply for a project I'm working on.

Pulled the psu out of the pc and found some nice helpful pages on how
to get it working stand alone, but I'm just running into dead ends.

The thing is it's a compaq psu (pdp-100 model) all non standard wire
colours, orange is brown etc etc, and add to that it has 24 wires not
20 or the 2 split plugs.

I have load (an old hard drive) on the 12 v and have found 2 wires
coming out that have voltage on them, tried grounding them both and
also tried using a 10hm resistor on them.

tried jumping pretty much every combination of colours to see if i get
a sign of life but nothing

putting load on to 5.5v

done a billion web searches with loads of things to do/try but nothing
worked.

put it all back together on plugged it back into the pc mother board
and dam thing works !!! grrr

wondered if any one has
- either used a compaq psu (non standard) before
- can offer and ideas, maybe by looking at the pcb or checking with a
multi meter
- something more drastic, like jump the sensing on the pcb



only thing I can find on the web code wise is the following but it may
not be correct !

1 brown +3V
2 brown +3v
3 black com
4 red +5V
5 black com
6 red +5V
7 gray aux com
8 purple ?
9 green +5V aux
10 orange +12V
11 pink +3V aux
12 white/red fan ?
13 brown +3V
14 blue -12V
15 black com
16 white (on stby)
17 black com
18 black com
19 black com
20 brown +3V
21 red +5v
22 red +5v
23 brown 3VRS (small dia wire)
24 white/blue fan sink


any help much appreciated

Ian

 

[Humphrey B. Bear]

Hi all

do hope somebody can help me out here !

I had an old compaq deskpro that was working but now replaced and
needed a 12v 2 amp supply for a project I'm working on.

Pulled the psu out of the pc and found some nice helpful pages on how
to get it working stand alone, but I'm just running into dead ends.

The thing is it's a compaq psu (pdp-100 model) all non standard wire
colours, orange is brown etc etc, and add to that it has 24 wires not
20 or the 2 split plugs.

I have load (an old hard drive) on the 12 v and have found 2 wires
coming out that have voltage on them, tried grounding them both and
also tried using a 10hm resistor on them.

tried jumping pretty much every combination of colours to see if i get
a sign of life but nothing

putting load on to 5.5v

done a billion web searches with loads of things to do/try but nothing
worked.

put it all back together on plugged it back into the pc mother board
and dam thing works !!! grrr

wondered if any one has
- either used a compaq psu (non standard) before
- can offer and ideas, maybe by looking at the pcb or checking with a
multi meter
- something more drastic, like jump the sensing on the pcb



only thing I can find on the web code wise is the following but it may
not be correct !

1 brown +3V
2 brown +3v
3 black com
4 red +5V
5 black com
6 red +5V
7 gray aux com
8 purple ?
9 green +5V aux
10 orange +12V
11 pink +3V aux
12 white/red fan ?
13 brown +3V
14 blue -12V
15 black com
16 white (on stby)
17 black com
18 black com
19 black com
20 brown +3V
21 red +5v
22 red +5v
23 brown 3VRS (small dia wire)
24 white/blue fan sink


any help much appreciated

Ian

Possibly you could measure the voltages on all wires going to the
motherboard while the computer is running, then measure them again when you
disconnect the PSU from everything. If one wire is at 0V when the computer
is running OK, but +5V when the PSU is disconnected, try connecting this
wire to ground and see if the PSU starts up. (Maybe it's the purple wire)

.... Humphrey

 

[Stanislaw Flatto]

Possibly you could measure the voltages on all wires going to the
motherboard while the computer is running, then measure them again when you
disconnect the PSU from everything. If one wire is at 0V when the computer
is running OK, but +5V when the PSU is disconnected, try connecting this
wire to ground and see if the PSU starts up. (Maybe it's the purple wire)

... Humphrey

That's THE way. Lets try it! Oh, shit!!!

(Did you notice that this group has a notion of science in title?)

Have fun.

Stanislaw
Slack user from Ulladulla.