Any ideas - PC stopped POSTing/booting

Hello
I have been having some trouble with a system I built back in May of
2007 that I wonder if anyone could help me with.

First, the system specs:
- ASUS M2N32-SLI Premium
- AMD Athlon 64 X2 5600+ Windsor 2.8GHz Socket AM2 89W Dual-Core
Processor
BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express
x16 SLI Supported Video Card
- (2x)G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
(a total of 4GB)
- RAIDMAX SMILODON ATX-612WBP Black SECC STEEL ATX Mid Tower Computer
Case 500W Power Supply
- erroneous periphs including 2 x 500GB Seagate SATAII drives running
as a RAID

This system has been working fine from the day I built it until three
weeks or so ago when I turned it on and when I went to use it after
waiting the usual boot time I found it had not booted. The fans and
LEDs were lit, and the speaker on the board is kind of muffled so I
wouldn't have noticed any beeps or lack of beeps. I did a hard reset
and got a "failed disk - need to reset BIIOS to defaults" warning
which I promptly ignored and allowed the system to boot as usual,
which it did.

Since then it has progressed to where cold booting could take upwards
of a dozen cycles of turning on the power switch/holding down for four
seconds to kill it - repeat before I get a beep and a normal POST and
boot. I will repeat that the fans/drives spin up and the case/mobo
LEDs light. There is no beep and no video. Once it finally does boot
the system runs *perfectly*. A hot restart has also been fine.

Anyway, I have been thinking it was the kind of crappy power supply
that came with the case so last night I went and bought a new Antec
500 watt Earthwatts PS to see if that would solve it. When I installed
the new PS and turned on the system I got the same symptoms that I
have been having except now I cannot get it to POST or boot at all.
The fans spin, etc, but no joy. I have stripped the board down to
nothing and taken it out of the case, etc, but this puppy is not doing
anything. But the lights and the fan(s) still spin...

I do not think that it's the PS (I know it's possible, but how likely
to have another different manufacturer/different purchase location
power supply crap out?). So, since I really need to get back to work
ASAP, I have overnighted the identical mobo and CPU from NewEgg and I
am thinking I can return whichever one is NOT the culprit ( not to
scam them - simply to return the item that I do not need)

My guess is that it's the board, but it looks fine.

Everything is exactly as I have described. I am the only one who uses
or touches this PC and it has not been opened or even moved since the
day I built it back in May

Does anyone have any ideas or thoughts on this? Also, if it is the
board, it is still under warranty. Does anyone have experience or tips
on dealing with Asus? I love their products, and I won't begrudge them
one bad experience out of the many good ones I have had with their
products, but fair is fair.

Thanks in advance for any thoughts or help with this perplexing
situation!
Please reply to this group and not my spam-trap hotmail email.

Paul

top-posting my own follow-up:

I wanted to add that I did reset he CMOS a couple of times as per
Asus' procedure and that this machine is not and has never been
overclocked. I have taken everything off the board including the RAM
and tried putting stuff back one at a time, etc


On Jan 31, 12:19 am, pauld <pauld...@hotmail.com> wrote:
> Hello
> I have been having some trouble with a system I built back in May of
> 2007 that I wonder if anyone could help me with.
>
> First, the system specs:
> - ASUS M2N32-SLI Premium
> - AMD Athlon 64 X2 5600+ Windsor 2.8GHz Socket AM2 89W Dual-Core
> Processor
> BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express
> x16 SLI Supported Video Card
> - (2x)G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
> (a total of 4GB)
> - RAIDMAX SMILODON ATX-612WBP Black SECC STEEL ATX Mid Tower Computer
> Case 500W Power Supply
> - erroneous periphs including 2 x 500GB Seagate SATAII drives running
> as a RAID
>
> This system has been working fine from the day I built it until three
> weeks or so ago when I turned it on and when I went to use it after
> waiting the usual boot time I found it had not booted. The fans and
> LEDs were lit, and the speaker on the board is kind of muffled so I
> wouldn't have noticed any beeps or lack of beeps. I did a hard reset
> and got a "failed disk - need to reset BIIOS to defaults" warning
> which I promptly ignored and allowed the system to boot as usual,
> which it did.
>
> Since then it has progressed to where cold booting could take upwards
> of a dozen cycles of turning on the power switch/holding down for four
> seconds to kill it - repeat before I get a beep and a normal POST and
> boot. I will repeat that the fans/drives spin up and the case/mobo
> LEDs light. There is no beep and no video. Once it finally does boot
> the system runs *perfectly*. A hot restart has also been fine.
>
> Anyway, I have been thinking it was the kind of crappy power supply
> that came with the case so last night I went and bought a new Antec
> 500 watt Earthwatts PS to see if that would solve it. When I installed
> the new PS and turned on the system I got the same symptoms that I
> have been having except now I cannot get it to POST or boot at all.
> The fans spin, etc, but no joy. I have stripped the board down to
> nothing and taken it out of the case, etc, but this puppy is not doing
> anything. But the lights and the fan(s) still spin...
>
> I do not think that it's the PS (I know it's possible, but how likely
> to have another different manufacturer/different purchase location
> power supply crap out?). So, since I really need to get back to work
> ASAP, I have overnighted the identical mobo and CPU from NewEgg and I
> am thinking I can return whichever one is NOT the culprit ( not to
> scam them - simply to return the item that I do not need)
>
> My guess is that it's the board, but it looks fine.
>
> Everything is exactly as I have described. I am the only one who uses
> or touches this PC and it has not been opened or even moved since the
> day I built it back in May
>
> Does anyone have any ideas or thoughts on this? Also, if it is the
> board, it is still under warranty. Does anyone have experience or tips
> on dealing with Asus? I love their products, and I won't begrudge them
> one bad experience out of the many good ones I have had with their
> products, but fair is fair.
>
> Thanks in advance for any thoughts or help with this perplexing
> situation!
> Please reply to this group and not my spam-trap hotmail email.
>
> Paul

Paul, watch my thread above, I'm having similar problems with an
A8N-SLI Deluxe

On Wed, 30 Jan 2008 23:19:38 -0800 (PST), pauld <>
wrote:

>wouldn't have noticed any beeps or lack of beeps. I did a hard reset
>and got a "failed disk - need to reset BIIOS to defaults" warning
>which I promptly ignored and allowed the system to boot as usual,
>which it did.
>
>Since then it has progressed to where cold booting could take upwards
>of a dozen cycles of turning on the power switch/holding down for four
>seconds to kill it - repeat before I get a beep and a normal POST and
>boot. I will repeat that the fans/drives spin up and the case/mobo
>LEDs light. There is no beep and no video. Once it finally does boot
>the system runs *perfectly*. A hot restart has also been fine.

first thing I'd try would be to open it up & make sure all cables were
properly plugged in .. data & power for hard drives

On Wed, 30 Jan 2008 23:19:38 -0800 (PST), pauld <>
wrote:

>Hello
> I have been having some trouble with a system I built back in May of
>2007 that I wonder if anyone could help me with.
>
>First, the system specs:
> - ASUS M2N32-SLI Premium
> - AMD Athlon 64 X2 5600+ Windsor 2.8GHz Socket AM2 89W Dual-Core
>Processor
>BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express
>x16 SLI Supported Video Card
> - (2x)G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
>(a total of 4GB)
> - RAIDMAX SMILODON ATX-612WBP Black SECC STEEL ATX Mid Tower Computer
>Case 500W Power Supply
>- erroneous periphs including 2 x 500GB Seagate SATAII drives running
>as a RAID
>
>This system has been working fine from the day I built it until three
>weeks or so ago when I turned it on and when I went to use it after
>waiting the usual boot time I found it had not booted. The fans and
>LEDs were lit, and the speaker on the board is kind of muffled so I
>wouldn't have noticed any beeps or lack of beeps. I did a hard reset
>and got a "failed disk - need to reset BIIOS to defaults" warning
>which I promptly ignored and allowed the system to boot as usual,
>which it did.
>
>Since then it has progressed to where cold booting could take upwards
>of a dozen cycles of turning on the power switch/holding down for four
>seconds to kill it - repeat before I get a beep and a normal POST and
>boot. I will repeat that the fans/drives spin up and the case/mobo
>LEDs light. There is no beep and no video. Once it finally does boot
>the system runs *perfectly*. A hot restart has also been fine.
>
>Anyway, I have been thinking it was the kind of crappy power supply
>that came with the case so last night I went and bought a new Antec
>500 watt Earthwatts PS to see if that would solve it. When I installed
>the new PS and turned on the system I got the same symptoms that I
>have been having except now I cannot get it to POST or boot at all.
>The fans spin, etc, but no joy. I have stripped the board down to
>nothing and taken it out of the case, etc, but this puppy is not doing
>anything. But the lights and the fan(s) still spin...
>
>I do not think that it's the PS (I know it's possible, but how likely
>to have another different manufacturer/different purchase location
>power supply crap out?). So, since I really need to get back to work
>ASAP, I have overnighted the identical mobo and CPU from NewEgg and I
>am thinking I can return whichever one is NOT the culprit ( not to
>scam them - simply to return the item that I do not need)
>
>My guess is that it's the board, but it looks fine.
>
>Everything is exactly as I have described. I am the only one who uses
>or touches this PC and it has not been opened or even moved since the
>day I built it back in May
>
>Does anyone have any ideas or thoughts on this? Also, if it is the
>board, it is still under warranty. Does anyone have experience or tips
>on dealing with Asus? I love their products, and I won't begrudge them
>one bad experience out of the many good ones I have had with their
>products, but fair is fair.
>
>Thanks in advance for any thoughts or help with this perplexing
>situation!
>Please reply to this group and not my spam-trap hotmail email.
>
>Paul

I had similar, not identical, problems with a very similar board, an
A8N-SLI Premium. I'd get through a POST and launch of Windows XP, but
the system would then mostly freeze (still had a mouse). On a warm
reboot, it was obvious that the HD (a Raptor) with the boot partition
on it was not being detected because POST would complete and end up
with a "no-system-disk" message. Powering down the computer at the
mains and restarting would almost invariably get the drive recognized
again. Once the drive was recognized, the computer ran "*perfectly*,"
just like yours. After a lot of troubleshooting, swapping SATA cables
and SATA ports, checking RAM, it turned out that the problem was a
failing drive. Replacing the HD with a clone resolved the problem.
Your "failed-disk" message makes me wonder if the BIOS is not
detecting a drive at all. My suggestion would therefore be to
download the free drive diagnostic software from your manufacturer in
order to make sure that your primary HD is not faulty. Also, if you
haven't tried switching drive cables, do that. Since you have a RAID
setup (almost always a bad idea on standalone computers, IMHO, but
beside the point here), I realize that it's very difficult to swap the
connections to different SATA connectors on the mobo, but if you can
do that, that also might be worth a try.

Ron

On Feb 1, 9:32 am, milleron <nos...@nospam.com> wrote:
> On Wed, 30 Jan 2008 23:19:38 -0800 (PST), pauld <pauld...@hotmail.com>
> wrote:
>
>
>
> >Hello
> > I have been having some trouble with a system I built back in May of
> >2007 that I wonder if anyone could help me with.
>
> >First, the system specs:
> > - ASUS M2N32-SLI Premium
> > - AMD Athlon 64 X2 5600+ Windsor 2.8GHz Socket AM2 89W Dual-Core
> >Processor
> >BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express
> >x16 SLI Supported Video Card
> > - (2x)G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
> >(a total of 4GB)
> > - RAIDMAX SMILODON ATX-612WBP Black SECC STEEL ATX Mid Tower Computer
> >Case 500W Power Supply
> >- erroneous periphs including 2 x 500GB Seagate SATAII drives running
> >as a RAID
>
> >This system has been working fine from the day I built it until three
> >weeks or so ago when I turned it on and when I went to use it after
> >waiting the usual boot time I found it had not booted. The fans and
> >LEDs were lit, and the speaker on the board is kind of muffled so I
> >wouldn't have noticed any beeps or lack of beeps. I did a hard reset
> >and got a "failed disk - need to reset BIIOS to defaults" warning
> >which I promptly ignored and allowed the system to boot as usual,
> >which it did.
>
> >Since then it has progressed to where cold booting could take upwards
> >of a dozen cycles of turning on the power switch/holding down for four
> >seconds to kill it - repeat before I get a beep and a normal POST and
> >boot. I will repeat that the fans/drives spin up and the case/mobo
> >LEDs light. There is no beep and no video. Once it finally does boot
> >the system runs *perfectly*. A hot restart has also been fine.
>
> >Anyway, I have been thinking it was the kind of crappy power supply
> >that came with the case so last night I went and bought a new Antec
> >500 watt Earthwatts PS to see if that would solve it. When I installed
> >the new PS and turned on the system I got the same symptoms that I
> >have been having except now I cannot get it to POST or boot at all.
> >The fans spin, etc, but no joy. I have stripped the board down to
> >nothing and taken it out of the case, etc, but this puppy is not doing
> >anything. But the lights and the fan(s) still spin...
>
> >I do not think that it's the PS (I know it's possible, but how likely
> >to have another different manufacturer/different purchase location
> >power supply crap out?). So, since I really need to get back to work
> >ASAP, I have overnighted the identical mobo and CPU from NewEgg and I
> >am thinking I can return whichever one is NOT the culprit ( not to
> >scam them - simply to return the item that I do not need)
>
> >My guess is that it's the board, but it looks fine.
>
> >Everything is exactly as I have described. I am the only one who uses
> >or touches this PC and it has not been opened or even moved since the
> >day I built it back in May
>
> >Does anyone have any ideas or thoughts on this? Also, if it is the
> >board, it is still under warranty. Does anyone have experience or tips
> >on dealing with Asus? I love their products, and I won't begrudge them
> >one bad experience out of the many good ones I have had with their
> >products, but fair is fair.
>
> >Thanks in advance for any thoughts or help with this perplexing
> >situation!
> >Please reply to this group and not my spam-trap hotmail email.
>
> >Paul
>
> I had similar, not identical, problems with a very similar board, an
> A8N-SLI Premium. I'd get through a POST and launch of Windows XP, but
> the system would then mostly freeze (still had a mouse). On a warm
> reboot, it was obvious that the HD (a Raptor) with the boot partition
> on it was not being detected because POST would complete and end up
> with a "no-system-disk" message. Powering down the computer at the
> mains and restarting would almost invariably get the drive recognized
> again. Once the drive was recognized, the computer ran "*perfectly*,"
> just like yours. After a lot of troubleshooting, swapping SATA cables
> and SATA ports, checking RAM, it turned out that the problem was a
> failing drive. Replacing the HD with a clone resolved the problem.
> Your "failed-disk" message makes me wonder if the BIOS is not
> detecting a drive at all. My suggestion would therefore be to
> download the free drive diagnostic software from your manufacturer in
> order to make sure that your primary HD is not faulty. Also, if you
> haven't tried switching drive cables, do that. Since you have a RAID
> setup (almost always a bad idea on standalone computers, IMHO, but
> beside the point here), I realize that it's very difficult to swap the
> connections to different SATA connectors on the mobo, but if you can
> do that, that also might be worth a try.
>
> Ron

The drives are irrelevant since I cannot get anything even with just
the board and CPU. I have just received a new board and CPU from
NewEgg, I put the old CPU in the new board and got nothing (when I
say nothing, I mean fans and lights are there, but no beeps). I put
the new CPU in the old board - nothing. I put the new CPU in the new
board with a new power supply - nothing. At this point I am beyond
perplexed since the last try has completely NEW components. I am going
to try different outlets since that's all that's left. There are other
PCs in the room where this mystery one is that work fine, but I am
running out of ideas.

I have been extremely careful throughout and I find it hard to imagine
that between two identical boards and identical CPUs I cannot get even
error beeps. I want to be clear-these boards are no longer in a case.
They are not connected to drives. I have tried them with CPU + Video
card + Keyboard + RAM and every combination in between. I just have no
idea outside of some fluke coincidence or underpowered outlet thing
that this board does not like - which I doubt.

Paul

On Feb 1, 2:47 pm, pauld <pauld...@hotmail.com> wrote:
> On Feb 1, 9:32 am, milleron <nos...@nospam.com> wrote:
>
>
>
> > On Wed, 30 Jan 2008 23:19:38 -0800 (PST), pauld <pauld...@hotmail.com>
> > wrote:
>
> > >Hello
> > > I have been having some trouble with a system I built back in May of
> > >2007 that I wonder if anyone could help me with.
>
> > >First, the system specs:
> > > - ASUS M2N32-SLI Premium
> > > - AMD Athlon 64 X2 5600+ Windsor 2.8GHz Socket AM2 89W Dual-Core
> > >Processor
> > >BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express
> > >x16 SLI Supported Video Card
> > > - (2x)G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
> > >(a total of 4GB)
> > > - RAIDMAX SMILODON ATX-612WBP Black SECC STEEL ATX Mid Tower Computer
> > >Case 500W Power Supply
> > >- erroneous periphs including 2 x 500GB Seagate SATAII drives running
> > >as a RAID
>
> > >This system has been working fine from the day I built it until three
> > >weeks or so ago when I turned it on and when I went to use it after
> > >waiting the usual boot time I found it had not booted. The fans and
> > >LEDs were lit, and the speaker on the board is kind of muffled so I
> > >wouldn't have noticed any beeps or lack of beeps. I did a hard reset
> > >and got a "failed disk - need to reset BIIOS to defaults" warning
> > >which I promptly ignored and allowed the system to boot as usual,
> > >which it did.
>
> > >Since then it has progressed to where cold booting could take upwards
> > >of a dozen cycles of turning on the power switch/holding down for four
> > >seconds to kill it - repeat before I get a beep and a normal POST and
> > >boot. I will repeat that the fans/drives spin up and the case/mobo
> > >LEDs light. There is no beep and no video. Once it finally does boot
> > >the system runs *perfectly*. A hot restart has also been fine.
>
> > >Anyway, I have been thinking it was the kind of crappy power supply
> > >that came with the case so last night I went and bought a new Antec
> > >500 watt Earthwatts PS to see if that would solve it. When I installed
> > >the new PS and turned on the system I got the same symptoms that I
> > >have been having except now I cannot get it to POST or boot at all.
> > >The fans spin, etc, but no joy. I have stripped the board down to
> > >nothing and taken it out of the case, etc, but this puppy is not doing
> > >anything. But the lights and the fan(s) still spin...
>
> > >I do not think that it's the PS (I know it's possible, but how likely
> > >to have another different manufacturer/different purchase location
> > >power supply crap out?). So, since I really need to get back to work
> > >ASAP, I have overnighted the identical mobo and CPU from NewEgg and I
> > >am thinking I can return whichever one is NOT the culprit ( not to
> > >scam them - simply to return the item that I do not need)
>
> > >My guess is that it's the board, but it looks fine.
>
> > >Everything is exactly as I have described. I am the only one who uses
> > >or touches this PC and it has not been opened or even moved since the
> > >day I built it back in May
>
> > >Does anyone have any ideas or thoughts on this? Also, if it is the
> > >board, it is still under warranty. Does anyone have experience or tips
> > >on dealing with Asus? I love their products, and I won't begrudge them
> > >one bad experience out of the many good ones I have had with their
> > >products, but fair is fair.
>
> > >Thanks in advance for any thoughts or help with this perplexing
> > >situation!
> > >Please reply to this group and not my spam-trap hotmail email.
>
> > >Paul
>
> > I had similar, not identical, problems with a very similar board, an
> > A8N-SLI Premium. I'd get through a POST and launch of Windows XP, but
> > the system would then mostly freeze (still had a mouse). On a warm
> > reboot, it was obvious that the HD (a Raptor) with the boot partition
> > on it was not being detected because POST would complete and end up
> > with a "no-system-disk" message. Powering down the computer at the
> > mains and restarting would almost invariably get the drive recognized
> > again. Once the drive was recognized, the computer ran "*perfectly*,"
> > just like yours. After a lot of troubleshooting, swapping SATA cables
> > and SATA ports, checking RAM, it turned out that the problem was a
> > failing drive. Replacing the HD with a clone resolved the problem.
> > Your "failed-disk" message makes me wonder if the BIOS is not
> > detecting a drive at all. My suggestion would therefore be to
> > download the free drive diagnostic software from your manufacturer in
> > order to make sure that your primary HD is not faulty. Also, if you
> > haven't tried switching drive cables, do that. Since you have a RAID
> > setup (almost always a bad idea on standalone computers, IMHO, but
> > beside the point here), I realize that it's very difficult to swap the
> > connections to different SATA connectors on the mobo, but if you can
> > do that, that also might be worth a try.
>
> > Ron
>
> The drives are irrelevant since I cannot get anything even with just
> the board and CPU. I have just received a new board and CPU from
> NewEgg, I put the old CPU in the new board and got nothing (when I
> say nothing, I mean fans and lights are there, but no beeps). I put
> the new CPU in the old board - nothing. I put the new CPU in the new
> board with a new power supply - nothing. At this point I am beyond
> perplexed since the last try has completely NEW components. I am going
> to try different outlets since that's all that's left. There are other
> PCs in the room where this mystery one is that work fine, but I am
> running out of ideas.
>
> I have been extremely careful throughout and I find it hard to imagine
> that between two identical boards and identical CPUs I cannot get even
> error beeps. I want to be clear-these boards are no longer in a case.
> They are not connected to drives. I have tried them with CPU + Video
> card + Keyboard + RAM and every combination in between. I just have no
> idea outside of some fluke coincidence or underpowered outlet thing
> that this board does not like - which I doubt.
>
> Paul

A big duh! I did not realize that you needed the ATX 12v plugged in
for single graphics cards - so the situation described above is null
and void. Hooking up the new power supply to the old board and CPU
has everything working though I am still suspicious of the board since
the old power supply works as well, though that may be because the
board has already booted a couple times and the problem has been cold
booting/posting all along.

Obviously when I assembled this rig in May I knew enough to plug in
the ATX power, but had forgotten. I work full time plus I am in grad
school plus I am not as young as I used to be.....oy.

For now I am holding on to the new board and CPU just in case.For all
I know it was something loose all along but I do not consider this
likely since I did quadruple check everything before I swapped out the
PS the first time around.

I am going to check out the drives as recommended and no matter what I
will post the ultimate resolution.

Paul

Paul

On Feb 1, 4:25 pm, pauld <pauld...@hotmail.com> wrote:
> On Feb 1, 2:47 pm, pauld <pauld...@hotmail.com> wrote:
>


After running numerous tests I think that the memory controller on the
original board is bad. The new board POSTs with any combination of RAM
and with either the old or new power supply, while the old board POSTs
intermittently and sometimes give bad memory beeps; indeed, when using
any of the four sticks of RAM in the A-1 slot the chance of error is
50-50 or better.

Paul

On Fri, 1 Feb 2008 17:55:38 -0800 (PST), pauld <>
when using
>any of the four sticks of RAM in the A-1 slot the chance of error is


The diagram for where to put the ram
sticks is a little confusing. Try putting in only one ram stick and
see if that helps.

That part about the onboard speaker being muffled sounds suspicious.
Try pulling the video card out and just use the motherboards video.

On Feb 1, 8:55 pm, pauld <pauld...@hotmail.com> wrote:
> After running numerous tests I think that the memory controller on the
> original board is bad. The new board POSTs with any combination of RAM
> and with either the old or newpower supply, ...

A primary reason for fixing things is to learn. Described is how to
learn from your mistakes. First things were replaced only on
speculation. Second, after so much labor, unknown is what is and is
not 'definitively good'. Third, a computer can still boot and run
even with defective parts such as a power supply. Fourth, a good
power supply can appear defective in another system for numerous
reasons. Included in that list: it is a power supply 'system' where
power supply is only one 'system' component.

Doors in a house were sticking. So we plane down all doors? No.
First we locate a reason for all those sticking doors. Common factor
is a defective foundation. Instead of fixing doors (curing symptoms),
identify and fix the foundation - the actual problem.

Foundation of a computer is its power supply 'system'. Until that
foundation is confirmed, then anything can act unstable or fail. Start
an analysis using a two minute procedure "When your computer dies
without warning....." starting 6 Feb 2007 in the newsgroup
alt.windows-xp at:
http://tinyurl.com/yvf9vh
Connector chart to locate each color:
http://www.hardwarebook.net/connecto.../atxpower.html

You speculated a power supply (and other parts) was defective rather
than first identify the suspect. A failure of any other part in that
power 'system' also could have made the supply appear defective.
Supply and other parts are still unknown. Replacing a power supply on
speculation is called shotgunning. If a power supply was defective,
then that two minute procedure would have identified it 'definitively
bad'.

Same applies to motherboard and to memory. Dont' shotgun. As said
in CSI, "Follow the evidence". Before replacing anything, first
identify a suspect.

More responsible computer manufacturers provide comprehensive
hardware diagnostics just for this reason. If your manufacturer is
not so responsible, then download diagnostics from each component
manufacturer or from third parties.

For example, memory can report failures if a power supply system is
"unknown". When ready to test memory, also execute that diagnostic in
a 100 degree room or with semicondutors heated by a hair dryer on
high. Diagnostics - especially when executed with memory warm - takes
memory from 'unknown' to either 'definitively good' or 'definitively
bad'.

As noted up top, learn by fixing things. Shotgunning results in
wastefully buying components. What is 'defintively good'?
Demonstrated is how to convert speculation into suspects - before
buying anything. There is no reason to buy parts until the suspect is
first identified. That procedure also results in less time and less
labor as well as money saved. Mistake was to shotgun. Fix things to
learn from mistakes. Fixing things should not result in replacing
perfectly good parts.

A last point. Normal for a computer to boot when its power supply
is defective. Supply could have been defective when system was first
built. Using that same two minute procedure would have identified a
defective power 'system' when computer was first assembled. How to
eliminate a strange computer failure before it happens.