Computer Shuts off, Stays Off

[Jack B]

The computer I built for my Mom three and a half years ago is acting up. It
just shuts down from time to time, and/or won't turn on at all sometimes.
For example, this morning I went over there and turned it on, and it shut
off after about 2 minutes. After waiting about 10 minutes, I was able to
turn it on again, but then it shut off and would not turn back on. When it
goes off, it's as if the power cord were pulled, that is, it does not do a
windows shutdown. However, the optical mouse light and keyboard lights stay
on, so I guess that means the main power cord at least is functioning. I've
tried the obvious stuff like wiggling the cord, and checking outlet and
power strip voltage.

I'm thinking that maybe replacing the power supply is the next thing to do,
but wondered if there is something else I could try before I do that. The
components and op system are listed below.

I'd appreciate any help with this.

Thanks,

Jack

Win XP home OEM $92

Shuttle AN35N Ultra mb $66

Athlon 2500 XP Barton $90

Seagate 40G 7200 $61

Lite on CDRW 52x32x52 52327s $39

MS Optical mouse $19

Gigabyte Radeon 7000 64mb video card $39

Kingston 512mb DDR333 PC-2700 Ram 1 stick $76

Antec case SLK3700AMB 350 watt $67

NEC 17" AS70 $119

 

[Frank McCoy]

The computer I built for my Mom three and a half years ago is acting up. It
just shuts down from time to time, and/or won't turn on at all sometimes.
For example, this morning I went over there and turned it on, and it shut
off after about 2 minutes. After waiting about 10 minutes, I was able to
turn it on again, but then it shut off and would not turn back on. When it
goes off, it's as if the power cord were pulled, that is, it does not do a
windows shutdown. However, the optical mouse light and keyboard lights stay
on, so I guess that means the main power cord at least is functioning. I've
tried the obvious stuff like wiggling the cord, and checking outlet and
power strip voltage.

I'm thinking that maybe replacing the power supply is the next thing to do,
but wondered if there is something else I could try before I do that. The
components and op system are listed below.

I'd appreciate any help with this.

Thanks,

Jack

Win XP home OEM $92

Shuttle AN35N Ultra mb $66

Athlon 2500 XP Barton $90

Seagate 40G 7200 $61

Lite on CDRW 52x32x52 52327s $39

MS Optical mouse $19

Gigabyte Radeon 7000 64mb video card $39

Kingston 512mb DDR333 PC-2700 Ram 1 stick $76

Antec case SLK3700AMB 350 watt $67

NEC 17" AS70 $119

Sounds like an overheating problem to me.

 

[Jack B]

Is the processor fan running immediately upon turning on the computer???
Is it turning freely? Is the heat sink clean and free of dirt? It could
be many things, even a poor connection with the RAM. But it sounds a lot
like heat is shutting it down.

I just tried again after the computer has been off for about 4 hours. When
I pressed the on button, both the CPU fan and the case fan spun normally and
freely, but the computer shut down only about a second or three after I
pushed the button.

 

[Ken]

The computer I built for my Mom three and a half years ago is acting
up. It just shuts down from time to time, and/or won't turn on at all
sometimes. For example, this morning I went over there and turned it on,
and it shut off after about 2 minutes. After waiting about 10 minutes,
I was able to turn it on again, but then it shut off and would not turn
back on. When it goes off, it's as if the power cord were pulled, that
is, it does not do a windows shutdown. However, the optical mouse light
and keyboard lights stay on, so I guess that means the main power cord
at least is functioning. I've tried the obvious stuff like wiggling the
cord, and checking outlet and power strip voltage.

I'm thinking that maybe replacing the power supply is the next thing to
do, but wondered if there is something else I could try before I do
that. The components and op system are listed below.

I'd appreciate any help with this.

Thanks,

Jack

Win XP home OEM $92

Shuttle AN35N Ultra mb $66

Athlon 2500 XP Barton $90

Seagate 40G 7200 $61

Lite on CDRW 52x32x52 52327s $39

MS Optical mouse $19

Gigabyte Radeon 7000 64mb video card $39

Kingston 512mb DDR333 PC-2700 Ram 1 stick $76

Antec case SLK3700AMB 350 watt $67

NEC 17" AS70 $119

Is the processor fan running immediately upon turning on the
computer??? Is it turning freely? Is the heat sink clean and free of
dirt? It could be many things, even a poor connection with the RAM.
But it sounds a lot like heat is shutting it down.

 

[Frank McCoy]

I just tried again after the computer has been off for about 4 hours. When
I pressed the on button, both the CPU fan and the case fan spun normally and
freely, but the computer shut down only about a second or three after I
pushed the button.

Again, sounds like an overheating problem.
I'd look at the fan, heatsink, and the heatsink clips holding it onto
the CPU. Something could have come loose. You might need to remove the
heatsink, blow it clean, check the fan to see if it spins easily,
replace it if necessary, clean off the CPU and heatsink mating parts,
put new "Arctic Silver" heatsink compound on the join, and then remate
the heatsink to the CPU afterwards.

Another possibility might be the power-supply giving out when the extra
load of the disk-drives come on line.

For that, simply disconnect one or more of the drives (hard-drives,
floppies, whatever); and if it runs *then*; the problem is likely the
PSU, not the drive (though it *could* be that, as well).

 

[kony]

You might unplug the PSU from AC for a few minutes then open
and inspect it. There's probably vented capacitors inside,
it's a known weakness on some Antecs and 3 years seems about
the right timeframe with moderate use. If that's the case
and you're handy with a soldering iron you might be able to
fix it youself... if you feel comfortable working on
something that will eventually be connected to AC line
voltage again though the caps that typically fail are on the
low voltage subcircuits.


This motherboard also has somewhat marginal capacitors that
could be prone to failure. Others have observed higher than
avg. failure rates from these caps (OST brand, IIRC, dark
blue or purplish with a gold stripe) although I've had a
very similar system (MN31N, the mATX version of that board)
running for a few years overclocked and voltmodded without
any problems, except that I added a fan to cool the VRM
subcircuit area which keeps the most stressed caps cooler.
http://69.36.166.207/usr_1034/nb_sinks/1.jpg



You might also check the video card, and/or pull it out and
try another one if you have a spare card as it is possible
another part besides the board or PSU is intermittently
shorting out, thus causing the PSU to turn off.

I just tried again after the computer has been off for about 4 hours. When
I pressed the on button, both the CPU fan and the case fan spun normally and
freely, but the computer shut down only about a second or three after I
pushed the button.

Unless the heatsink had come completely off (which would be
obvious), and since we presume the heatsink has stayed on as
it had been while the system ran successfully for over 3
years, it should prevent the processor from overheating this
quickly even if the fan had failed. If none of the
motherboard capacitors look vented, the PSU is the primary
suspect. Often I might advise taking multimeter voltage
readings of a suspect PSU but in this case it might go from
proper voltage to a critical shutdown threshold quickly
enough that voltage readings may not reveal the problem.

You could try pulling out the PSU and shorting the PS-On pin
to a black ground pin with a paperclip/etc to see if the PSU
will remain running while connected to nothing, but with
some PSU they may require at least a slight load to regulate
properly and connecting a PSU with potentially bad output
might jeopardize the connected part... so a load resistor on
the 5V and 12V rails would be the safest alternative, or an
old worthless hard drive, but if you have no such parts then
trying to power it with nothing connected is the best first
try.

http://69.36.166.207/usr_1034/atx_on.gif

Since the system is fairly basic, with low current demand
and does use 12V rail to power the CPU power subcircuit
(unlike some Athlon XP generation systems), any reasonable
quality ATX 2.03 300W+ PSU should be a good replacement.

 

[Ed M.]

I just tried again after the computer has been off for about 4 hours.

When I pressed the on button, both the CPU fan and the case fan spun
normally and freely, but the computer shut down only about a second or
three after I pushed the button.

Just from experience, that particular problem 'usually' turns out to be
a power supply. Everything spins up and then it just stops. 90% of the time
I see that, a new PSU will fix it. The fact that it sometimes will start
normally before it will shut down kind of makes me lean towards the PSU
rather than overheating. It doesn't eliminate it though.


Ed

 

[Jack B]

Just from experience, that particular problem 'usually' turns out to be
a power supply. Everything spins up and then it just stops. 90% of the
time I see that, a new PSU will fix it. The fact that it sometimes will
start normally before it will shut down kind of makes me lean towards the
PSU rather than overheating. It doesn't eliminate it though.


Ed

Thanks for all the advice, everyone. I will swap in a PSU later today and
post results back to the group.

Jack

 

[Jack B]

Well, I threw in an old Dell 200 Watt PSU that I had lying around, and the
computer will not turn on at all. Is it possible that the 200 W PSU does
not have enough power for a start up? If that's the case, I will buy a new
350 W and try it.

BTW, earlier this morning with the orginal power supply, the computer turned
on and ran for about a minute before shutting down. However, the case was
open and all fans were running up to the shut down.

Thanks,

Jack

 

[Jack B]

I bought a new PSU and put it in, and I still have the same problem. Any
suggestions on what to try next? I guess I could remove the CPU and reseat
it. Anything else?

Thanks,

Jack

 

[Frank McCoy]

I bought a new PSU and put it in, and I still have the same problem. Any
suggestions on what to try next? I guess I could remove the CPU and reseat
it. Anything else?

Not just reseat it.
Look *very* closely at the heatsink on the thing.
Is it flat and level; and does it have good soft heasink compound on it?

 

[kony]

Well, I threw in an old Dell 200 Watt PSU that I had lying around, and the
computer will not turn on at all. Is it possible that the 200 W PSU does
not have enough power for a start up? If that's the case, I will buy a new
350 W and try it.

Yes it's quite possible, could depend a lot on whether that
Dell 200W PSU is a fairly new model optimized for a lot of
12V current, or an older model with fairly split or mostly
5V current capability.

BTW, earlier this morning with the orginal power supply, the computer turned
on and ran for about a minute before shutting down. However, the case was
open and all fans were running up to the shut down.

If the PSU is failing, it "might" be possible that the lower
the current demand from it, the longer it would stay
running. Therefore, I suggest if you get it running for
long enough to do so, you go into the bios and manually set
the slowest FSB speed it can use to temporarily underclock
it, then power off and unplug all non-cricital parts leaving
only CPU, heatsink/fan, one memory module and video card (an
old very low power video card would be even better like an
early '90s PCI card or ATI Rage /XL series (cards with such
lower power use that they don't even have heatsinks on their
GPU).

With the other parts unplugged from data and power cables,
system cold, turn it on and go into the bios health/hardware
monitor screen and observe the reported voltages and temps
up until it shuts off, if it does. It may report the
voltages a little lower than actual, on my MN31N with MBM
(Motherboard monitor) 5.3.7.0 it's reporting 11.8V on 12V
rail and 4.08V (!?) on 5V rail while idling in windows.
Maybe I never bothered to set up MBM correctly for this
board, as I didn't care about it monitoring 5V rail at the
time (not an important system/use), but when I saw the 4.08V
report it caused me to check the PSU output directly with a
multimeter and while reporting 4.08V/11.8V the PSU was
outputting 5.1V/12.3V.

Anyway, while watching the health monitor page it should
indicate if the temps are rising to any alarming level up to
the point when it shuts down, but it still seems most likely
to be electrical like a PSU problem, or a failing powered
part causing the PSU to shut down from it's overcurrent
protection.

 

[kony]

I bought a new PSU and put it in, and I still have the same problem. Any
suggestions on what to try next? I guess I could remove the CPU and reseat
it. Anything else?

Which problem? Shutting down or failing to start like with
the Dell 200W?

If you are certain the new PSU is a good brand of
appropriate wattage & current on the 12V rail (suggest a
rating of at least 14 honest amps on 12V), therefore leaving
only a small chance the PSU were defective instead of the
other pre-existing problem still being present, then as
already mentioned you might remove the heatsink and reattach
it, and disconnect all parts non-essential towards getting
the system to POST, but if all else fails it would tend to
implicate the motherboard. Did you examine it for failed
capacitors? (Particularly those to the bottom left of the
CPU socket).

Also I don't recall if that board has a fan failure shutdown
feature/setting, but if it does and one of your fans has
dropped down below a certain RPM threshold, that could also
cause it to turn off. You could test this by holding the
(processor fan, or whichever fan is plugged into the
processor or northbridge? fan header pins) fan still while
the system is turned on, if the feature is present it would
turn off the system in a few moments, long before not having
the fan spinning would result in it overheating to a
critical level.

 

[DaveW]

The PSU replacement that you suggested is the correct place to start. If
that doesn't fix it, then it is likely that the motherboard has developed a
thermal fault and needs replacement.

 

[Jack B]

Which problem? Shutting down or failing to start like with
the Dell 200W?

If you are certain the new PSU is a good brand of
appropriate wattage & current on the 12V rail (suggest a
rating of at least 14 honest amps on 12V), therefore leaving
only a small chance the PSU were defective instead of the
other pre-existing problem still being present, then as
already mentioned you might remove the heatsink and reattach
it, and disconnect all parts non-essential towards getting
the system to POST, but if all else fails it would tend to
implicate the motherboard. Did you examine it for failed
capacitors? (Particularly those to the bottom left of the
CPU socket).

Also I don't recall if that board has a fan failure shutdown
feature/setting, but if it does and one of your fans has
dropped down below a certain RPM threshold, that could also
cause it to turn off. You could test this by holding the
(processor fan, or whichever fan is plugged into the
processor or northbridge? fan header pins) fan still while
the system is turned on, if the feature is present it would
turn off the system in a few moments, long before not having
the fan spinning would result in it overheating to a
critical level.

The problem now is that the computer does not start at all. This is with
the new power supply. A light flashes briefly when I push the start button,
and sometimes a fan just starts to move, but that is it.

 

[Jack B]

Any thoughts on what mb to buy - I don't need anything special as my Mom
does no more than surf the net a bit and check email. It's got to be
compatible with the parts now on board - Athlon socket A, DDR333 PC-2700
mem, AGP. I'm not sure how to read specs to know a board meets all of that.

 

[kony]

The problem now is that the computer does not start at all. This is with
the new power supply. A light flashes briefly when I push the start button,
and sometimes a fan just starts to move, but that is it.

You didn't tell us anything about the new PSU. Is it good?
A known trustworthy brand with sufficient current rating on
12V rail?

If so, it would seem either the board is bad or (you never
did mention what else you're doing to isolate things) some
part you haven't unplugged is bad.

 

[kony]

Any thoughts on what mb to buy - I don't need anything special as my Mom
does no more than surf the net a bit and check email. It's got to be
compatible with the parts now on board - Athlon socket A, DDR333 PC-2700
mem, AGP. I'm not sure how to read specs to know a board meets all of that.

Do you need all those PCI slots? If so, get a full ATX
board with nForce2 chipset. If not, it opens up the
opportunities for nForce2 mATX also. All nForce2 support
DDR333, all are socket A, and AGP. Main question is where
you want to buy it, if you're willing to spend the time you
might get it cheaper, but only so much time is reasonable to
spend. The typical good brands are MSI, Asus, Gigabyte,
Abit... though as I'd mentioned, my shuttle MN31N still
works so I don't consider it too bad either, and I have a
Biostar M7NCG nForce2 board that has also held up better
than I'd expected it to, though it's bios is a bit buggy
with a wierd memory quirk requiring it not be set to CAS3
for the memory... it's actually more stable at CAS2.5 even
when the modules are CAS3 rated.

 

[Jack B]

You didn't tell us anything about the new PSU. Is it good?
A known trustworthy brand with sufficient current rating on
12V rail?

If so, it would seem either the board is bad or (you never
did mention what else you're doing to isolate things) some
part you haven't unplugged is bad.

The new PSU is an Antec BP350 that I bought at Circuit City for $40. It
would be an unlikely coincidence that this brand new PSU, plus the one I
removed from the computer, plus the old 200 PSU I tried were all bad, so I
think the problem must be elsewhere.

I disconnected both the hard drive and the CD Rom drive and the computer
still does not start (once in a while it starts, but only runs for a few
seconds). I've taken the memory out and reseated it and no change. I see
the capacitors you've mentioned, but I don't know how to check if one or
more are bad. I haven't pulled the heat sink or CPU, as it's a little
awkward getting at it and I don't want to force anything. Anyway, since the
main problem is that the computer won't start at all, even after it's been
sitting for hours, I'm thinking heat is not the problem.

I guess I'll buy a board online, and swap that in, unless someone has
another suggestion.

Thanks,

Jack

 

[Paul]

Any thoughts on what mb to buy - I don't need anything special as my Mom
does no more than surf the net a bit and check email. It's got to be
compatible with the parts now on board - Athlon socket A, DDR333 PC-2700
mem, AGP. I'm not sure how to read specs to know a board meets all of
that.

The best fit, would be to find another Nforce2 motherboard.
This is your previous motherboard (AN35/N Ultra). You may
find something on Ebay.

http://tw.shuttle.com/Product/MotherBoard/mbd_Spec.asp?M_id=49

The problem is, there aren't a lot of S462 boards left at retail.
So you don't get the best boards any more, just the low end
stuff.

This is what Newegg has left. Chipset is SIS746FX.

PC CHIPS M848A (V5.0) A (462) SiS 746FX ATX AMD Motherboard $55
http://www.newegg.com/Product/Product.aspx?Item=N82E16813185074

A 2500+ is FSB333 (166Mhz clock times 2). That fits the Newegg
description OK. This is the table I use for Athlons and speed ratings.

http://web.archive.org/web/20031018050306/http://www.qdi.nl/support/CPUQDISocketA.htm

The Radeon 7000 AGP pictured here, has both slots cut in the connector,
so it looks like a universal AGP card. That will plug into the
1.5V slot on the PC Chips board. And the playtool.com link confirms
that the 7000 AGP would work with SIS746.

(Picture of Radeon 7000 AGP...)
http://www.ixbt.com/video2/images/over-2003/r7000.jpg

More info on mixing and matching video cards and chipsets is here.
Just so you can verify this is OK yourself.

http://www.playtool.com/pages/agpcompat/agp.html

The only problem with a PCChips board, is the odds that it will work
properly when you get it. Have a look at the customer reviews, as there are
a couple hundred here, and that will give you some idea what to
expect.

http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16813185074

Pricewatch will give you some idea as to what other boards are left at retail.
You can check the sellers via resellersratings.com

http://www.pricewatch.com/motherboards/socket_462.htm

This is the rating for GearXS.com (2.5 out of 10). Not a good rating.

http://www.resellerratings.com/store/GearXS

Whatever board you get, you'll need to do a Repair Install of
Windows, and that will give you an opportunity to load in some
new drivers.

http://www.michaelstevenstech.com/XPrepairinstall.htm

OK, final shot, is to go with a modern setup, and use built-in
graphics (i.e. ditch the 7000 and use a Geforce 6100 and its
built-in chipset graphics). The processor is quite cheap, and yet
should outperform the existing one by a slight bit.

AMD Socket AM2 processor 3200+ $44
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103031

CORSAIR ValueSelect 1GB (2x512MB) DDR2 SDRAM DDR2-533 (PC2-4200) $33
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145526

ASRock ALIVENF6G-VSTA AM2 NVIDIA GeForce 6100 or 6150SE / nForce 430 $55
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157108

The 1GB of RAM, is to make up for the use of built-in graphics, which
would use some of the system RAM. AM2 has dual channel capability, so
I spent an extra couple dollars and used a dual kit of memory. Total
price of the AM2 solution would be $132, and you could use your old
power supply. So the solution does cost more than the $55 for the
PCchips board. But you could have your choice of AM2 boards, and some
of the Gigabyte boards got good ratings in the Newegg list. They are
around $75, about $20 more than the ASRock I used as a placeholder above.

HTH,
Paul