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by genece / October 5, 2006 12:17 AM PDT

You folks helped me with a couple questions on memory and just as I was about to purchase some additional memory ...when I started to have a boot problem....After a while I thought to check voltages so I downloaded MBM5 and sure enough the voltages seemed low
these are est. as I did not write them down
5 volt = 4.85
12 volt 11.8
3 volt 1.45.

so I had another PS here so I installed it and the voltages are better but the 3 volt line is still only 2 volt ...is that OK?
P4 2.4 3200 DDR.
XP Pro
The old PS was an Antec 350W
the new a Termaltake 450w
Voltages with new PS 12.3----5.2------2.0

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I'd verify that with a voltmeter.
by R. Proffitt Forum moderator / October 5, 2006 12:40 AM PDT
In reply to: Voltages

Motherboard monitors have poor accuracy so double check yours with the real deal.


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Is that the orange wire?
by genece / October 5, 2006 1:16 AM PDT

orange 3volt?
yellow 12volt
red 5 volt.

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Blue wire.
by R. Proffitt Forum moderator / October 5, 2006 1:28 AM PDT

Has -12 Volts and the white wire should have -5 Volts.



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Voltage Tolerances
by Darton Fury / October 5, 2006 7:14 AM PDT
In reply to: Blue wire.

PSUs put out DC voltage that can vary from the correct value by as much as -10% to +10%. The 12V line can vary from 10.5 to 12.9 volts and the 5V and 3.3V offer the same tolerances.

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colors & voltages
by superchuckles / October 5, 2006 11:21 PM PDT
In reply to: Voltages

ok, atx supplies (unless it's propriatary) are
12v+ yellow
5v+ red
3.3v+ orange
12v- blue
5v- white
gnd - black
with 5v+ standby on purple
ps-on on green
power good on gray
and the 3.3v+ sense wire on brown

don't rely on motherboard monitor for accurate voltage readings unless you first find out the actual voltage with a reliable digital voltmeter first. if the voltmeter says your 12v+ line is actually 12.4v & motherboard monitor says it's 11.9v, then you know that the voltage comparitor in the motherboard is off by a few tenths (hopefully linear error, so when mbm shows 12v, you'll know it's actually 12.5) as far as the 3v showing 2, i'd check it, but.... i wouldn't sweat it. motherboard monitor is notorious for certain motherboards showing that kind of thing.

if you want to make sure your voltmeter is nearly dead on accurate, measure the voltage on your bios button cell. lithium batteries will hold almost all their rated voltage right up until they die, so unless your motherboard is over 6 years old, it's likely it will read 3v. good luck.

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Thanks to all
by genece / October 6, 2006 11:30 PM PDT
In reply to: colors & voltages

After checking with a meter the 12 and 5 volt readings are correct but the 3 volt reading is way off I get 3.42 volts.......
But I am glad I changed the PS as it fixed my stability problem.
Now I guess I will try the memory upgrade.

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3 volt is...
by R. Proffitt Forum moderator / October 7, 2006 12:11 AM PDT
In reply to: Thanks to all

Actually 3.3V +/- 5% so yours is in spec.


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