Re: P4P800 deluxe 3.3V problem...

TRON wrote:
hi..
my system is:
P4P800 Deluxe bios 1019.005
P4 3.0E (no overclock)
Cosair DDR 400 512mbX4
Leadtek 7800GS AGP
Seagate SATA 320GB HDD X2 @ RAID 0 on ICH5R
Maxtor IDE 160GB @ VIA IDE
Audigy2ZS
LG DVDRW
LG CDRW
80mm Casing Fan X 7
Thermaltake Xaser III 2000A Casing
Acbel 450W Intelligent PSU
+5v 30A
+3.3v 30A
+12v1 21A
+12v2 20A

i use this PSU 1year+, but few weeks ago, i had the problem with the 3.3V, the ASUS probe 2 show that the 3.3v drop to 2.90v ,but not "always" ,around "2.90~3.25". and i remember the first time i use this PSU the 3.3v show in the ASUS probe is around 3.40v.
but even 2.90v, the pc still working fine, no hang or restart itself. but i no know is it danger to other hadware?

so i try this PSU on other machine:
Abit K9NS
AMD Athlon X2 4000+
DDR2 667 1GB X1
2 HDD (160GB + 320GB seagate sata)
ASUS 1950Pro
LG DVDRW

the 3.3V is "normal" (around 3.31~3.39)

then i open up the PSU [void the warranty :-( ] and there is no sign of capacitor leaking(mainboard also). then after i reinstall the PSU, the 3.3v now show 3.25v, but after 1 day, the 3.3+ start to drop slowly ,around 0.1v per day!! untill now 2.90v !
i also try minimun the power usage :

512 RAMx1
HDD x 0
GF4 MX 440
P4P800 Deluxe
Casing fan X0
then when boot up, i go into bios check the voltage , the 3.3v still too low. around 2.90v~3.1v


anyone know what is the problem?
thanks..


While the hardware monitor chip can give some useful information about
power supply voltage, you should double check the values using a
multimeter. With the multimeter set to DC volts, you can probe the exposed
metal on the backside of the main power connector, to get some idea what
value the 3.3V is really showing.

Acceptable voltage values are shown on page 10. Pinout on page 30.
Orange wires are 3.3V. Black is ground.

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

If you don't wish to make the measurements, then buy another
power supply and swap it into place.

Whether the motherboard is at fault, would be determined with an
amperage measurement on the 3.3V. But that is too expensive a
measurement to make for most people. I use a clamp-on DC ammeter
to make such measurements. My P4C800-E and 9800Pro video card
for example, draw about 14 amps from the 3.3V rail. Which would
not bother your 30 amp output rail rating at all. As long
as the current draw is less than the output rating, the voltage
should still remain good (within +/- 5%).

HTH,
Paul
.

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