A7V600 - low voltage problem

  • Thread starter Thread starter Stefan vom Bruch
  • Start date Start date
S

Stefan vom Bruch

Hi!

I have been using the A7V600 for a couple of months without problems
now. But a few days ago my machine developed the problem that it froze
up just minutes after booting.

Using Asus Probe I have now traced the problem to low voltage on the
3.3V line. It starts off at 3.2V and continually drops. When it drops
below 2.8V, the machine will eventually freeze up.

What could be the problem? The PSU, the mainboard, too many PCI-cards or
one card using too much power?

My curent setup:
A7V600 mainboard
PSU: Thermaltake III Silent Purepower 480W (about nine months old)
CPU: XP2700+
RAM: 2x512MB KingMax PC3200
AGP: ATI AIW 9800 Pro
PCI: Soundblaster Audigy
PCI: Netgear Wireless LAN WG311
PCI: Adaptec IDE RAID Controller 1200A
PCI: Adaptec SCSI Controller 2930U2

TIA,
Stefan
 
Stefan said:
Hi!

I have been using the A7V600 for a couple of months without problems
now. But a few days ago my machine developed the problem that it froze
up just minutes after booting.

Using Asus Probe I have now traced the problem to low voltage on the
3.3V line. It starts off at 3.2V and continually drops. When it drops
below 2.8V, the machine will eventually freeze up.

What could be the problem? The PSU, the mainboard, too many PCI-cards or
one card using too much power?

My curent setup:
A7V600 mainboard
PSU: Thermaltake III Silent Purepower 480W (about nine months old)
CPU: XP2700+
RAM: 2x512MB KingMax PC3200
AGP: ATI AIW 9800 Pro
PCI: Soundblaster Audigy
PCI: Netgear Wireless LAN WG311
PCI: Adaptec IDE RAID Controller 1200A
PCI: Adaptec SCSI Controller 2930U2

TIA,
Stefan
Click to expand...

Your PCI cards consume relatively little power. The video card
can be up to 70W while playing 3D games, much less in the
desktop. One estimate is [email protected] and 5V@10A for a 9800 or 5950
class video card.

Either something is wrong with the PSU, the ATX 20pin connector
is not making good connections, the ATX 3.3V sense line has become
disconnected, or there is a partial short somewhere.

Many (but not all) ATX PS share the energy of the same primary
transformer winding. Output voltage is established by the turns
ratio of the output windings. The ATX connector has a 3.3V pin with
two wires joined to the same pin, and one of the wires is a remote
sense. When the remote sense detects the output voltage dropping,
it instructs the primary to "crank it up".

Typically, when one output is overloaded, you'll see the other
outputs rise higher than nominal. This happens as long as the
power supply is still under closed loop (feedback) control.
You don't mention how the +5V and +12V are reading, so I cannot
comment on whether this confirms a particular diagnosis or not.

Since so many people have trouble with their power supplies,
the odds right now are that the PS needs to be replaced. It is
either that, or somehow the ATX connector is not working properly,
to carry the current from the supply into the motherboard. Try
unplugging and replugging the ATX 20 pin connector.

HTH,
Paul
 
Hi!

I have been using the A7V600 for a couple of months without problems
now. But a few days ago my machine developed the problem that it froze
up just minutes after booting.

Using Asus Probe I have now traced the problem to low voltage on the
3.3V line. It starts off at 3.2V and continually drops. When it drops
below 2.8V, the machine will eventually freeze up.

What could be the problem? The PSU, the mainboard, too many PCI-cards or
one card using too much power?
Click to expand...

You probably know the answer to this one yourself. The power supply has
obviously got to be the first suspect... maybe the cheapest too.

If that doesn't do the trick I would be inclined to pull all the cards out...
just in case one of them is pulling the line down, and lastly the mobo.

John
 
Stefan said:
Hi!

I have been using the A7V600 for a couple of months without problems
now. But a few days ago my machine developed the problem that it froze
up just minutes after booting.

Using Asus Probe I have now traced the problem to low voltage on the
3.3V line. It starts off at 3.2V and continually drops. When it drops
below 2.8V, the machine will eventually freeze up.

What could be the problem? The PSU, the mainboard, too many PCI-cards or
one card using too much power?
[...]
Click to expand...
Your PCI cards consume relatively little power. The video card
can be up to 70W while playing 3D games, much less in the
desktop. One estimate is [email protected] and 5V@10A for a 9800 or 5950
class video card.

Either something is wrong with the PSU, the ATX 20pin connector
is not making good connections, the ATX 3.3V sense line has become
disconnected, or there is a partial short somewhere.
[...]
Click to expand...

Yes, it was the connector. I cleaned it and plugged it in again and
now it is a steady 3.31 - 3.33V.
Sometimes it is the little things. I experiment so much with different
compontents that I tend to blame it on one of them.

Thanks a lot for your advice. It is very much appreciated.
Stefan
 
Back
Top