mobo/ps issues

[jstotler]

I just picked up a 2800+ with a via mobo. I promptly popped it into my
old case, fired it up, and watched it randomly shut itself down. I
thought it could be several different things, and eventually shut down
all the lan/sound/usb/etc on the motherboard, and got as far as
launching a game once, and then <bam> it shut down again.

Then I installed cpuburn. I discovered that the instant I put a load on
the machine, it died. Well. Mobo or PS?

So tonight I picked up a new case with a 400watt PS. I dropped
everything in, fired it up, and it died while booting, once Fedora
started initing all the network/audio/etc hardware.

Now, docs that came with the mobo list the following reqs:

3.3V=25 Amps (or more)
5V=25 Amps (or more)
12V=15 Amps (or more)

The old PS was definitely below spec. The new one is good on all fronts
except the 3.3V, where it's only got 22Amps instead of 25.

Would this cause the shutdown?

I'm tending to lean toward a bad mobo, but it takes over a week to ship
back to the company I bought it from, and then another week to get a
new one back, assuming they actually rush one out...

Is there some sort of standard/spec I can be looking for on boxes to
deal with the mobo? It seems odd that I should have to bust into the
cases to read the UL stickers on the power supplies....

thanks,
fnord

 

[David Maynard]

I just picked up a 2800+

A 2800+ *what*? XP? Sempron? Athlon 64?

with a via mobo. I promptly popped it into my
old case, fired it up, and watched it randomly shut itself down. I
thought it could be several different things, and eventually shut down
all the lan/sound/usb/etc on the motherboard, and got as far as
launching a game once, and then <bam> it shut down again.

Then I installed cpuburn. I discovered that the instant I put a load on
the machine, it died. Well. Mobo or PS?

So tonight I picked up a new case with a 400watt PS.

Would help to know *what* case and PSU but if it's a generic then the odds
of that 400W PSU being able to handle 400 Watts is almost non-existant.
They use meaningless 'peak power' ratings akin to the equally useless 'peak
music power output' used to claim that 7 Watt speakers are 360W PMPO speakers.

I dropped
everything in, fired it up, and it died while booting, once Fedora
started initing all the network/audio/etc hardware.

Now, docs that came with the mobo list the following reqs:

3.3V=25 Amps (or more)
5V=25 Amps (or more)
12V=15 Amps (or more)

I don't suppose you're powering anything else too, like maybe a video card,
hard drive(s), CD/DVD(s), or lord knows what.

The old PS was definitely below spec. The new one is good on all fronts

By checking the 'max' or 'peak' numbers? 'Peak' amps is meaningless.

except the 3.3V, where it's only got 22Amps instead of 25.

Would this cause the shutdown?

Just off hand I'd say that 22 is less than 25.

I'm tending to lean toward a bad mobo,

Why? When you have one listed power requirement clearly not met?

but it takes over a week to ship
back to the company I bought it from, and then another week to get a
new one back, assuming they actually rush one out...

Is there some sort of standard/spec I can be looking for on boxes to
deal with the mobo? It seems odd that I should have to bust into the
cases to read the UL stickers on the power supplies....

From your description I'd guess the PSU before the motherboard but it
could also be a poorly installed heatsink, maybe on backwards, or without
thermal compound, or without removing the compound protective plastic. In
either of those situations the processor would overhead and cause a
shutdown. Might even run for a bit but overheat under load.

 

[w_tom]

To answer your question, the numbers must have better
validity. For example, does that power supply even provide
the numbers? Does your motherboard really require all those
currents? This is why informed computer assemblers use
another tool as important as the screwdriver. The 3.5 digit
multimeter is so ubiquitous as to even be sold in Home Depot,
Radio Shack, WalMart, Sears, and Lowes. The procedure, that
takes two minutes to answer your questions is summarized in
two previous posts:
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
http://tinyurl.com/2t69q
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

Not only must those numbers reside in the upper 3/4 limits
in that chart. Also post those numbers here so that others
can provide even further useful information.

Those numbers are best taken when the computer as accessing
as many peripherals as possible at the same time. IOW sound
card plays music from CD, as modem accesses internet, as
network interface accesses hard drive on another computer, as
floppy drive directory is read repeatedly - all simultaneously
while voltages are read with the meter.

And no, motherboard monitor will not provide sufficient
numbers. You need that meter to determine if power supply is
sufficiently sized. Only with those numbers can someone
provide a definitive answer. From data as provided, we can
only speculate.

 

[w_tom]

To answer your question, the numbers must have better
validity. For example, does that power supply even provide
the numbers? Does your motherboard really require all those
currents? This is why informed computer assemblers use
another tool as important as the screwdriver. The 3.5 digit
multimeter is so ubiquitous as to even be sold in Home Depot,
Radio Shack, WalMart, Sears, and Lowes. The procedure, that
takes two minutes to answer your questions is summarized in
two previous posts:
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
http://tinyurl.com/2t69q
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

Not only must those numbers reside in the upper 3/4 limits
in that chart. Also post those numbers here so that others
can provide even further useful information.

Those numbers are best taken when the computer as accessing
as many peripherals as possible at the same time. IOW sound
card plays music from CD, as modem accesses internet, as
network interface accesses hard drive on another computer, as
floppy drive directory is read repeatedly - all simultaneously
while voltages are read with the meter.

And no, motherboard monitor will not provide sufficient
numbers. You need that meter to determine if power supply is
sufficiently sized. Only with those numbers can someone
provide a definitive answer. From data as provided, we can
only speculate.

 

[spodosaurus]

I just picked up a 2800+ with a via mobo. I promptly popped it into my
old case, fired it up, and watched it randomly shut itself down. I
thought it could be several different things, and eventually shut down
all the lan/sound/usb/etc on the motherboard, and got as far as
launching a game once, and then <bam> it shut down again.

Then I installed cpuburn. I discovered that the instant I put a load on
the machine, it died. Well. Mobo or PS?

So tonight I picked up a new case with a 400watt PS. I dropped
everything in, fired it up, and it died while booting, once Fedora
started initing all the network/audio/etc hardware.

Now, docs that came with the mobo list the following reqs:

3.3V=25 Amps (or more)
5V=25 Amps (or more)
12V=15 Amps (or more)

The old PS was definitely below spec. The new one is good on all fronts
except the 3.3V, where it's only got 22Amps instead of 25.

Would this cause the shutdown?

I'm tending to lean toward a bad mobo, but it takes over a week to ship
back to the company I bought it from, and then another week to get a
new one back, assuming they actually rush one out...

Is there some sort of standard/spec I can be looking for on boxes to
deal with the mobo? It seems odd that I should have to bust into the
cases to read the UL stickers on the power supplies....

thanks,
fnord

check your heatsink and thermal compound. You should have redone the
thermal compound after moving the motherboard and cpu around anyway as
the interface was likely disrupted.

--
spammage trappage: replace fishies_ with yahoo

I'm going to die rather sooner than I'd like. I tried to protect my
neighbours from crime, and became the victim of it. Complications in
hospital following this resulted in a serious illness. I now need a bone
marrow transplant. Many people around the world are waiting for a marrow
transplant, too. Please volunteer to be a marrow donor:
http://www.abmdr.org.au/
http://www.marrow.org/

 

[larry moe 'n curly]

2800+ with a via mobo.
watched it randomly shut itself down.

Then I installed cpuburn. I discovered that the instant
I put a load on the machine, it died.

new case with a 400watt PS.
fired it up, and it died while booting, once Fedora started

Now, docs that came with the mobo list the following reqs:

3.3V=25 Amps (or more)
5V=25 Amps (or more)
12V=15 Amps (or more)

The old PS was definitely below spec. The new one is
good on all fronts except the 3.3V, 22Amps instead of 25.

Is there some sort of standard/spec I can be looking for on
boxes to deal with the mobo?

I've never seen a mobo box or manual with the power requirements
listed, but there are some power estimators on the web, one of the best
being at http://takaman.jp , but like almost all others its estimates
are a lot higher than actually need, although for some reason Takaman's
+3.3V amps figure should be doubled or tripled).

A couple of German websites took measurements a few years ago and found
that an Athlon XP2400+ system that used the +12V rail for the CPU (had
square 4-pin power connector w/ 2 yellow & 2 black wires) needed
roughly 8-10A @ +12V, 2-4A @ +5.0V, and 9-12A @ +3.3V. XP2400+ systems
that instead used the +5.0V rail for the CPU (no 4-pin power connector)
needed about 17-20A @ +5.0V and just 2-4A @ +12V. If you convert these
numbers to watts (volts x amps of each voltage rail, then add the
products), you'll find that they total less than 200W, and one person
found that his Athlon64 w/ fast graphics card and a bunch of HDs (incl.
two 10,000 RPMs) consumed only 400W max -- from the AC outlet,
indicatig that the computer drew only about 300W. Unfortunately the
typical 300W or even 400W PSU won't run such a computer because too
many manufacturers exaggerate their ratings, nor will many cheapo 600W
PSUs.

What manufacturers do the PSU registration numbers from UL (RU -- see
www.ul.com) and CSA (www.csa.ca) indicate? If they point to a company
like L&C, also known as Deer, that's bad news.

 

[jstotler]

Thanks for the advice, everyone. In the end, I had just put the
heatsink on backwards, so the CPU would crank right up and overheat and
shut down the system.

I've been doing this since my first 386sx25, I can't believe I ran into
something so stupid.


fnord

 

[Kadaitcha Man]

larry moe 'n curly, <[email protected]>, the acellular, bleeding
dope, and seller of ineffectual patent medicines, protested:

I've never seen a mobo box or manual with the power requirements
listed

That's because you're a ****ing moron and a cheap ****.

From the manual for my workstation MB (Intel SE7505VB2 Server Board):

"Your power supply must provide minimum of 450w with 2A standby current,
which meets the SSI EPS 12V specification."

HTFH & HANFD, you dumb ****.