P2 or Not 2P2?

  • Thread starter Thread starter George Hester
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George Hester

This is a questuion about a Power Supply.

A OLD Power Supply that came originally with the system is 250W. It has a
P2 connector. The line that P2 connector is on also has a P3 connector.
The colors and number of the wires in this group are:

1 Yellow (in and out)
2 Black (in and out)
1 Red (in and out)

These wires go on to another connector P3:

1 Yellow (in)
2 Black (in)
1 Red (in)

This group ends.

Now in my NEW Power Supply 300W there is only one connector labled and it is
P2. That "group" is

1 Red (in)
2 Orange (in)
3 Black (in)

That's the end of that group.

Obviously these Power Supplies are not similarly set up. My new one is a
ATX-300GT by FSP Group Inc. The old one I cannot identify. It has
electrical tape wound around it and I do not want to take it off for I know
not the consequences of doing so.

There are other groups of connectors on the NEW Power Supply that match the
OLD Power Supply as described above. Trouble is the labeling is
non-existant on the NEW except for the P2 connector I described above.

From what I can tell this P2 connector (Group) on the NEW Power Supply will
not be used anywhere. Does that sound right?
 
George said:

George:

Were the P1 and P2 connectors on your old supply connected to anything? If
not, and there is only an ATX connector on your mb, all you need to do is
plug the BIG "P1" connector on your new supply into the ATX power connector
on your mb and you should be all set (assuming you have connected the power
cables for all your disks and so forth (the PA, PB, ... PH connectors)).
My understanding is that the little "P1" connector is for powering a P4
cpu, which you don't have, and P2 is the mystery connector put on most
modern power supplies to confuse all of us people who don't use
motherboards manufactured in the 21st century. No seriously, P2 is the ATX
auxillary power connector, which if you have that P2L97-DS mb like I think
you do, isn't an issue since there's no socket for it.

http://www.asus.com/pub/ASUS/mb/slot1/440lx/p2l97-ds/p2l97ds-104.pdf

(p-11)

Remember, if this were really that complicated, Bill Gates would have
electrocuted himself as a teenager.
 
George, double check what the motherboard is. If it is 'of that age' then it
is quite likely that it takes an AT not ATX power supply, so you may be
looking for the wrong type of PSU.

AT power supplies are characterised by the motherboard connector being two
plugs that plug in side by side with all the metal plug pins being in one
line. They also have horrible hook like nothces on them.

The ATX connectors are more Teflon like with two rows of pins in a teflon
Plug (PSU end) / Socket (mobo end) arrangement. I don't recall an AT
motherboard plug being made of teflon - they predate a lot of things :)

The model of the motherboard should be written quite clearly on it - usually
in the middle.

They didn't need much power in those days - 250watts may seem small, but
that was usually enough then although server class AT PSU's could be 600
watts.

If it is a P2B-DS it is a good buy. I never had a P2L97. I have a DS here
that still runs 24 x 7. They will run Windows 2003 Server without fuss
(P2B-DS) - just a little slow, but smoooooth.

- Tim
 
P2B-DS???

P(entium) II B(oard)-D(?)S(?)

The machine is all packed up at this time so I cannot get to the MB. But
I'll be going back into it soon and will try to get the MB specs. I looked
but really couldn't find anything. There was identification there but too
much stuff to move around so didn't get into it.

The case is a Full ATX case. Isn't that what ATX means in a Power Supply
the configuration of the mounting screws?

--
George Hester
_______________________________
Tim said:
George, double check what the motherboard is. If it is 'of that age' then it
is quite likely that it takes an AT not ATX power supply, so you may be
looking for the wrong type of PSU.

AT power supplies are characterised by the motherboard connector being two
plugs that plug in side by side with all the metal plug pins being in one
line. They also have horrible hook like nothces on them.

The ATX connectors are more Teflon like with two rows of pins in a teflon
Plug (PSU end) / Socket (mobo end) arrangement. I don't recall an AT
motherboard plug being made of teflon - they predate a lot of things :)

The model of the motherboard should be written quite clearly on it - usually
in the middle.

They didn't need much power in those days - 250watts may seem small, but
that was usually enough then although server class AT PSU's could be 600
watts.

If it is a P2B-DS it is a good buy. I never had a P2L97. I have a DS here
that still runs 24 x 7. They will run Windows 2003 Server without fuss
(P2B-DS) - just a little slow, but smoooooth.

- Tim
 
I refrain from attributing anything to the motherboard names, except the
suffixes on certain cases (IE it is fruitless). -D tends to mean dual, -S
SCSI, -L Lan and so on. -DS is dual with onboard SCSI.

The ATX spec changed a few things for PSU's.
AT had a pushbutton power switch that was Mains voltage and Live. IE
dangerous. ATX uses a microswitch that requests power on and is safe. In
some countries you were supposed to be a qualified electrician to service
PC's... with AT PSU's.

AT had the single line Motherboard plug outlined, the ATX has Dual Line /
teflon covered plug and socket arrangement - easier all around. The ATX
supplies more signals to the motherboard and the CPU has a return signal to
the PSU - "Power OK" which tells the PSU that it is allowed to turn on the
power when the power microswitch has been pushed. IE the CPU can veto power
on if it detects eroneous things.

ATX also has 5V standby power (1 or 2 amps depending on the era of the PSU
and system needs). This powers the RAM and Wake On XXX devices (EG LAN
cards, K/B interface etc.) The idea behind this is that the system can be
woken as the necessary devices are power to a level where they can detect
activity (EG Lan, Phone Ring, Mouse action etc.).

Best of luck

- Tim





George Hester said:
P2B-DS???

P(entium) II B(oard)-D(?)S(?)

The machine is all packed up at this time so I cannot get to the MB. But
I'll be going back into it soon and will try to get the MB specs. I
looked
but really couldn't find anything. There was identification there but too
much stuff to move around so didn't get into it.

The case is a Full ATX case. Isn't that what ATX means in a Power Supply
the configuration of the mounting screws?
 
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