Gudday.
I have a P65UP5 with dual Pentium Pro's. The PSU died, so after hunting
around I managed to get an equivalent wattage PSU (230Watts).
This new PSU has indications of:
3.3Volts.
normal voltges
and
Black COM Return
Green P-ON Remote
Gray PG P-OK
The old PSU had not indications of any of these 'funcitons' although of
course the power connectors have the same colour coding.
The machine is completely dead. The power and Turbo LED's do not light up -
I have tried both in both ways, but the CPU heatsink fans both spin as does
the PSU fan. I have stripped the m/b to CPU's, memory & Graphics only. No
beeps at all. I reset the CMOS.....
Does anyone know if the PSU is suitable or not?
Any hints are really appreciated.
Fortunately (or not) this is not my machine....
Thanks, Tim
First of all, did you download a manual ? If you use the Asus download
page, there appear to be four models matching P65UP5, but they all seem
to use the same manual. I guess there are options or something.
Start by looking at page 24:
http://www.asus.com.cn/pub/ASUS/mb/sock8/440fx/p65up5/p65up5-204.pdf
+5V (RED)
+5V (RED)
+5V (RED)
-5V (WHITE)
GND (BLACK)
GND (BLACK)
GND (BLACK)
GND (BLACK)
-12V (BLUE)
+12V (YELLOW)
+5V (RED)
PG (ORANGE)
So, the motherboard doesn't have a requirement for 3.3V. I think the
motherboard uses an AT power supply, whereas today ATX power supplies
are much more common. I think an AT supply is only controlled by the
power switch on the back of the computer, whereas the ATX can be
controlled not only by the switch on the back, but also by connecting
the PS_ON# signal to GND (COM). Since the new power supply you bought
has a P_ON signal, maybe it is an ATX supply ? I'm confused...
This won't prevent it from working, and it sounds like somehow you've
got power flowing from it. Make sure that the pinout of the P9
and P8 six pin sections above match what you are plugging in. Each
hole should be occupied with a power pin, because if you only
connect one +5V wire, for example, too much current ends up flowing
through one pin and the pin in the connector can overheat or burn
the plastic. The connection on that pin can end up being intermittent
after that (I know because I've had that kind of trouble in the past
with this style connector).
If this was my motherboard, I would start by preparing a matching
pinout from supply to motherboard. With the power supply disconnected
from the motherboard, take a cheap multimeter and measure the voltage
on each pin you plan on connecting, to make sure you haven't made any
wiring errors. Then, power down and connect the PS to the motherboard.
If it still doesn't start, maybe the reason the old power supply
died, is because one of the supply rails on the motherboard has become
shorted to GND. This can happen, for example, if some of the
electrolytic capacitors have leaked or dried out and they are now
shorting the rails they are filtering. The capacitors can be replaced,
and there are plenty of posts in the Abit newsgroup to be found in
groups.google.com on replacing caps. There is even a guy who will do
the entire board for roughly $50, but that is too much money to spend
on a project like this.
ATX power supply connector - short PS_ON# to an adjacent COM, to have
an "always on" supply of power. Then, pick the pins you need, to get
power to whatever electronics project you are doing:
What an ATX connector looks like:
http://www.formfactors.org/developer/specs/atx/atx2_1.pdf (pg.19)
Example of an AT power supply (the first I could find):
http://www.pcpowerandcooling.com/support/docs/G230S.htm
If the new supply is being overloaded, perhaps the PG (Power_Good)
signal is never asserted by the power supply to the motherboard.
The motherboard operation should be gated (prevented from operating)
unless the PS tells the motherboard it is happy. If the AT supply
uses positive true logic (and I don't have an AT spec, so I don't
know this), you might see +5V on the PG pin when it is happy, or a
voltage closer to 0V when it is not.
HTH,
Paul
