ATX 12V/P4 Connector

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I have a PSU without a ATX 12/P4 4-pin plug a nice older 400 Watt Antec. but I have an extra one I cut off from a dead $20 PSU(No hardware died) can I just solder it to a molex splitter I cut up? 12V yellow to the 2 yellow wires and black ground to the 2 black wires? and would it work fine? as long as everthing is insulated? thanks this is for an AMD MB that has that connection

 

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come on i'm building a rig soon please help

 

[Ice Czar]

yup, just make sure that
1. you actually have the amps for the config your running
2. you get the +12V wires and the GND\COMs to the right pins

Good Luck

 

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Here is the config:
MSI K7N2GM-L N-Force2(MS-6777) (http://www.msicomputer.com/product/detail_spec/product_detail.asp?model=K7N2GM-L)
CPU AMD Athlon XP 2200+
512MB Ram
OS & Programs and Data
Maxtor 6Y80PO 7200RPM 80GB ATA133 With 8 MB Cache FDB Motor
Video Drive:
Maxtor 6Y160PO 7200RPM 160GB ATA133 8MB Cache FDB Motor
(http://www.maxtor.com/)
DVD/CD-RW Samsung SM-322
NIC Built in to MotherBoard
ATI All In Wonder Radeon 32MB DDR Graphics Card

With an INWIN MATX case and my 400Watt antec PSU is that succifent?

 

[Ice Czar]

I come up with
+3.3V @ 4.7Amps
+5VF @ 7.5Amps
+12V @ 12.4Amps
as raw numbers (theoretical maximum draw)
assuming a 9600 Pro at
+3.3V @ 2.9A
+5V @ 0.5A
+12V @ 0.6A
PC3200 and a few fans

so for a Antec Smart Power 400 Watt
Temperature................@ 25C.........@ 40C
+3.3V..........................28A...............18.6A
+5V.............................38A...............25.3A
+12V...........................18A...............12A

and an Antec PP403X
Temperature................@ 25C.........@t 40C
+3.3V..........................28A...............18.6A
+5V.............................40A...............26.6A
+12V...........................12A...............8A

so for starters your case is never going to see 25C unless its parked outside in Siberia
or your running one seriously hopped up AC directly into it,
that is offset by the fact that all you components never need their maximum load at the same time

a PP403X is out of the question
and a Smart Power is closer that Id like to run personally
given a high draw of multiple components at full power and too high a temperature
you might have intermittent problems

in addition running closer to a supplies full capacity impacts its life expecancy
power supplies are all about the worse case senerio
and I havent mentioned the last variable
if there is a brownout (a sag in the AC voltage from say 110 to 90)
that is really hard on the PSU,
and along with too high an operting temperature and load,
can kill a PSU that is operating too close to the edge
(hopefully it would safely shutdown without letting an overshoot through to the mobo or taking a bullet itself)

 

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ITs PC 2700 or DDR 333
and it an old all in wonder. It says radeon 7200 (It works fine only to record tv and I don't play games on that comp) and my Antec power supply says "Smart Power , Smart Fan and model PP-403X

 

[Ice Czar]

Well I have a PP403X and they date back to 1GHz Athlons and PIII's
it is definately not up to the task on the +12V rail
most of its capacity is on the shared +3.3V & +5V rail
which back then powered the CPU and mobo
the +12V rail was only for HDDs, Opticals and Fans
but as youll note the CPU is eating 5.6A on the +12V rail in that config
or 67Watts of capacity off the +12V rail, even when you eliminate the video card
(not sure exactly what that one draws but think it will be somewhere around a Ti4200)'
I still come up with 14A on the +12V rail
(100% utilization of fans and drives)

http://takaman.jp/D/?M=PbQOQbR3SASfTKTnUsZAZavPCMZ&english

the PP403X is a fine supply of basic compliance and was a "star" monster supply in its day
but its just not up to the task in a modern +12V biased computer
it might even power up that config until it gets too hot, then has to deal with an added draw of an optical and a little sag in the source power, instability in PSUs is all about the worse case senerio which is why PSUs are notorious as the source of "intermittent" problems, and that supply is suceptible with that load

the +12V rail will get hit something like this
at startup when the supply is cold and thus able to produce nearly its full rating of amps the HDDs and Fans will draw their full load to overcome inertia and spin up, then they will draw one quarter of that load once spinning, meanwhile your CPU will not be drawing its full load, unless there is some sort of problem (100% utilzation), add in a little more if your booting from a CD or accessing a CD at startup

so once your running the +12V rail will look good, however the supply will start to heat up as its exhausting the CPUs heatsink and do to its own inefficiency, thus its capacity will start to drop, but where its really suceptible is if the AC source power sags (brownout)

As the voltage is reduced, the PSU has to draw more current (Amps) in order to maintain the output voltages. The actual power drawn by the PSU rises when the input voltage is reduced. This is why, for example, that a power supply rated for 120VAC, 5A might be rated for 240VAC, 3A. Maintaining steady output voltage lines becomes much harder with lower or varying AC voltage. This is how PSU voltage regulation can be really tested.
http://www.silentpcreview.com/article166-page2.html

so with an Optical firing up and a higher CPU usage you could be in real trouble
with only 8 amps at the likely operating temperature and 6.6Amps draw at full load for the CPU\GPU and say another amp static draw from all the fans and HDD puts you at 7.6 amps start an Optical and that is 8.1amps

in other words you have a zero safety margin
ambient in the room gets too high you crash
brownout you crash, wrong combination of component load you crash

hope that gives you a little insight into the process

 

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Thanks for that the PSU the case came with is a Powerman ATX 12V which I beleve to be a sparkle/forton PSU it is only 240W put the 12V line has higher max amps that that antec does 16A VS 12

 

[Ice Czar]

yup Powerman's are typically rebranded FSP Group supplies
and FSP is conservative in rating their supplies

It should work out for that config
which isnt particularly demanding
funny how watts doesnt mean much these days

but log the voltage with MBM and keep an eye on it
especially when the room ambient increases

Good Luck

 

[darktiger]

I am having the same problem. Need to find a spare ATX 12/P4 4-pin plug.

 

[Ice Czar]

http://www.molex.com/cgi-bin/bv/molex/index_login.jsp

but again if it doesnt have a connector
it likely doesnt have the amps to run it either