Dewayne Thomas said:
I'm running a ASUS P4C800 deluxe in a tower case with XP OS and
suddenly I start getting low 3.0 Voltage warings from ASUS's probe.
System seems to be running stable. I switched PS and get almost the
identical readings. System as follows:
P4C800 Deluxe
P4 Northwood 2.8 Cpu (not overclocked)
1 G Memory (2/512 sticks Crucial PC4200 `
CPU Temp 32 Deg C
Case Temp 33 " "
Radeon 9600 SE AGP
12,5 & core voltage normal
I guess my question is how reliable is ASUS's probe. Its the probe
that came with the MB.
Personally, I feel that the purpose of the onboard monitor,
is to warn you that something is wrong. Voltages should be
checked using a multimeter, to tell what is really up, as a
multimeter can be more accurate than the monitor chip.
The monitor chip itself should be pretty reliable. If there
is a problem with the internal voltage reference in the
monitor, then all measurement channels should be thrown off
by the same percentage value. For one channel to misbehave,
would require a change in the two voltage divider resistors
on that channel, which is not too likely. Maybe the point
on the motherboard, at which the monitor is connected, is
really at 3.0 volts for some reason ?
If your power supply has the old 1x6 power connector, there
is a 3.3V pin on there, that you could probe with a multimeter.
Finding a 3.3V signal on the surface of the motherboard may
be a bit more difficult. (You want to check both the power
supply output level, and the 3.3V rail voltage on the surface
of the motherboard, to tell if there is a problem with a
bad connection on the ATX power supply connector.) If you
know the pinout of PCI or AGP slots, you could find a 3.3V
pin somewhere in there. Up near the ATX 20 pin connector,
you could probably also gain access to a 3.3V conductor, by
tracing the copper near the pins.
Remember that the P4C800 can draw 14 amps or so from 3.3V
while it is running at 100% CPU load. So there is a bit of
current flowing in the 3.3V power supply wires, and if some
copper conductor is not conducting well, it would be pretty
easy for the voltage to drop to 3.0V.
Paul
