Comp restarts.

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Here is the spec for my system,

Processor:        Intel Core 2 Duo E8500 3.16GHz
Motherboard:   Asus P5E3 Deluxe with Intel X38 chipset
Ram:                Mushkin Enhanced 2x1GB DDR3 1333MHz;
Graphics Card: Asus GeForce 9800GTX 512Mb
Sound Card:     Creative SoundBlaster Audigy 2 ZS
Harddisk:          2 x WD120GB and 1 x WD320GB
DVDRW:          Pioneer 18X drive
PSU:                CoolerMaster Extreme Power Duo 650W with SLI ready

I'm using Windows XP SP2. My problem is that my system would restarts itself
during bootup (sometimes 2 or 3 times). This usually happens just as it
enter windows, at the screen after the windows logo and before the desktop.
I'm not sure but I think my problem could be my PSU being not as efficient
as rated (at 70%) or it could be overheating (as I've read at that this model is
considered to have a pretty small heatsink for its power rating). But the
system runs without errors after entering windows.

The reason I'm saying it could be my PSU is that when I plug in only two of
my HDD (2x120GB running in RAID 0) it boots up fine, no restarting. But when
I plug in my third HDD (1x320GB) the problem starts. I can't figure it out,
could my 1x320GB hdd be consuming thats much power? Or could it be some
software problem or even a virus?

Also I'm using only a 4pin ATX12V connector for my motherboard's EATX12V
while the board uses a 8pin EPS + 12V power plug for the . Could this be the

Any help would be greatly appreciated.


Re: Comp restarts.

Jerry Chong wrote:
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Dear Jerry

What you are describing is what is called an "Open Neutral or floating
ground"  In short what is happening when you connect your third hard
drive the return path for the current is through the control cabling and
not the power cabling and what this does is to cause all sorts of
unusual voltages to be present.  This problem is very difficult to
troubleshoot because of the weird nature of the symptoms. This could be
an intermittent open in the cabling or an actual loose connection in the
power supply itself.  This is a very common problem in the construction
industry and very hard to find in a large buildings, but the same laws
of physics apply in both cases.  I would be suspicious of 4 pin ATX12V
set up in regards as to loose grounds and the like. No software problem
and not likely to be a virus; however, both of those are easy to trouble
shoot compared to a floating neutral.

Good Fortune


Re: Comp restarts.

On Fri, 30 May 2008 21:00:35 -0700, lkboop

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Is the drive detected correctly in the bios POST
enumeration?  If possible boot to the hard drive
manufacturer's diagnostics and check the drive for errors.
Those diags are avaiable from WD's website if you dont' have
them (might've come in a retail drive package).

You wrote that it restarts sometimes 2 or 3 times but then
what?  Does it eventually keep booting all the way into
windows if you try a 4th time if/when required to?

Does it only happen from a cold start, or also if you turn
off the system and turn on after it'd been running long
enough to be warm still, or also if  you choose
shutdown->restart from windows or hit the case reset butto
instead of turning the system completely off?

Try booting to safe mode, does it still happen then?

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That should not matter, in particular it could mean over
time that excessive heat made the capacitors pop, or some
instability with a higher load like when gaming which I
assume you do (having 9800GTX video card) but since you
haven't mentioned any other symptoms of instability we'll
probably assume the only issue that stands out is that which
has been mentioned.

If your PSU isn't under warranty anymore and all else fails,
unplug it from AC for a few minutes and inspect it,
particularly the caps near where the exiting wiring harness
attaches to the PCB.

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That would make overheating unlikely (or even if it were
overheating to some extent, that might shorten it's lifespan
but wouldn't cause _only_ this problem).

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Try plugging it into only power, not data, then booting
windows.  If that works ok, odds are windows is erring and
rebooting because it can't deal with what it finds.  Then
the question arises as to whether this config worked
previously without any changes inbetween the period when it
last worked and now doesn't.  If it did then we might more
likely suspect the hard drive is failing, but of course
there are small chances it could be many things and we lack
some info that you know as I've pointed out or asked in
various places in my reply.  It's not totally impossible
that you have a PSU problem, but unlikely that it would work
to stabily initialize the system, pass POST, boot to windows
without one drive and work ok at all times except with this
one drive added.  The added drive uses less power than
putting your system under some load in windows, like gaming
or running a CPU stress test (Orthos for example).

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No, it shouldn't be consuming over 15W, if that.  Video card
alone consumes more just switching from 2D mode into 3D
mode, before even starting gameplay.  CPU alone consumes
more just going from half utilization state booting to full
load state on a demanding multithreaded task.  IF it only
happened when the system were cold, I would more likely
suspect bad connectors, broken or cracked trace, or the
beginnings of a capacitor failure that will get worse over

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Yes it definitely could be a "problem" per se, definitely it
is part of the problem in the result you see, but that
doesn't necessarily mean there is some hidden windows button
or registry entry that would fix it, it would tend to mean
windows isn't fault tolerant and if windows can't gracefully
keep booting when a problem arises, you have to get rid of
the cause to get rid of the observed effect.

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Unplug your 4 pin connector and examine it's contacts, and
the mating contacts on the board connector.  If they look
burnt or have a distorted shape then it may be a problem,
but in general no, your processor does not use enough power
that you need more than the 2 x 2, 4 pin connector to supply
that power.  If you were extremely overclocking, then it
might be an issue but as the system stands it should be fine
unless the contacts where damaged or defective in some way,
and if this were the case then you would see an extreme drop
in voltage when doing a stress test like Orthos, and
instability that effected other things long before it
mattered if you had one hard drive connected or not while

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That is an interesting theory, but there is no evidence of
this and it is exceedingly rare if possible, when one
considers that there are at least 4 points of ground for a
typical hard drive:

1)  Data cables.  All grounds together would probably be
enough to carry the slight current a drive uses, though IF
it were the only ground path then perhaps it could indeed be
a problem since these are signal path wires.  Even so,
beyond enumeration windows needs little to no communication
because it's booting from the other two in the RAID0 array
(presumably, it seems the only reasonable conclusion to draw
based on the rest of the info).

2)  Chassis.  HDD frame is common ground with PCB, connected
by metal screw (usually) to conductive HDD rack which is
common to motherboard ground.

3)  Two power plug ground leads.  Even if one were bad, the
second is there and either alone could carry more current
than the drive consumes, plus if both were bad we would have
to wonder why and that it would seem as likely to have
effected the 5V or 12V lines as well, equally or really
moreso than ground pins since there is only one 5V or 12V
lead per connector.  I should pause and say that I am only
considering the older 4 pin molex now, not SATA plugs.

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While I don't know if what you are describing is common in
the construction industry or not, the odds are low for it to
be occurring with a hard drive in the computer industry,
particularly one that manages to be detected and otherwise
functional (as far as we know?).

For the time being there is at least one thing the OP can do
to rule out the suspicion of the added drive overtaxing the
power supply.  The drive power cable can be plugged in but
the data cable removed, so that power consumption is
practically identical but windows does not see this drive
when trying to boot.

I'm betting this is a software problem, that windows errs
when it finds something it can't work around, perhaps the
drive itself is damaged physically or logically, or there is
a motherboard setting or bios flaw.  So there might be more
than one problem, the resultant problem only manifesting
itself when a subsystem it depends on isn't working
properly.  The initial problem will take more digging, might
be a drive failing or jumper bad, bad data connector/cabling
or something else.

What we dont' know yet is if this combination had ever
worked, whether it just stopped booting in the same config
that had worked previously, or if something about the system
had changed prior to the onset of the problem.

Re: Comp restarts.

Jerry Chong wrote:

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That's a pretty good indication of a PSU being too weak for the system
and not that you have a floating ground.  Here's a real review of a
660W AcBel, the actual manufacturer of your CoolerMaster (if its registration is E131375).  By "real" I mean the PSU was loaded
down to its full rated power and not just with a computer system,
which is usually a load of just 200-300W.

Notice that it failed the 378W test, even when the PSU was tested at
25C, or 5-15C cooler than a typical computer interior.  It's normal
for maximum output capacity to drop at higher temperature, and this
proportion is typical for lesser designs.  OTOH what
said about the heatsinks being too small may not be true because even
first-rate PSUs, like Seasonics, use seemingly skimpy heatsinks in
their models that have large fans.  Also I don't see how the reviewer
can conclude anything about the heatsinks without taking their
temperatures.  BTW, said that a 450W AcBel PSU was
better than the 660W one.

Never trust PSU reviews that don't include amp numbers.  Some of the
very few websites that do good PSU testing include,,,,,, and

Don't trust power ratings, badly done reviews, or customer ratings..
It's safer to trust brands, and has a list of good and
bad products.

Re: Comp restarts.

On Sat, 31 May 2008 05:28:54 -0700 (PDT), "larry moe 'n

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IMO, the linked test is just about worthless because no
variables were isolated.  There is no mention of trying the
test at a lower temp, for all we know it is as likely that
the reason for shutdown was the low load on the 5V rail.
While there are some things the hardwaresecrets reviews do
well, it is fairly invalid to define a test and apply a PSU
against that test, instead of recognizing what was rated -
the rail current ratio, and accumlating data about under
which variables it fails.

We can say one thing for certain, in the linked test #4,
there is no way it overheated enough to cause shutdown in 10
seconds.  Similarly so in test 5, these are almost certainly
output threshold limits exceeded.

Key is the remark made on the page,
"Over current protection (OCP) circuit was active and
shutting down the power supply whenever we tried to pull
more than 21 A from any +12 V rail."

... and yet, when dual rails aren't truely, completely
independent, that may be what was happening in test #3 with
a 14A + 14A load on both 12V rails.  What is more important
is that we don't know what the true limit if this PSU is,
but it is reasonable to suspect that the OP's system was not
drawing 28A @ 12V.  I'd guesstimate OP's CPU and video card
were consuming under 200W during boot, maybe 10W per HDD (on
12V rail), add maybe 20W more watts for fans and optical
drive if it were spinning and you have 230W or 19A which is
pretty close to the Test #2 linked above for 12V rail
consumption... and that test #2 at 45C no less, which is
below what a typical case ambient temp would be after having
only been on for less than a minute booting windows.

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The PSU may indeed be bad, but I find it hard to believe one
hard drive would make or break it while booting, but it
never showed instability any other time (like when gaming
which is a higher load).

Re: Comp restarts.

kony wrote:

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Could it be that increased the power draw on not
only the +12V rails but also the +5V and +3.3V rails because that
reflects what more-power-hungry computers draw?  I'm just speculating
because I've never seen numbers for amps on reach rail versus overall
power consumption.

After test #4 resulted in failure, it was repeated at 25C, but the PSU
soon shut down again.  Also some PSUs have passed all of's test, and at least one other website, maybe, listed an AcBel PSU among those that could not put
out their rated power in a ~25C environment.

Re: Comp restarts.

On Mon, 2 Jun 2008 07:30:22 -0700 (PDT), "larry moe 'n

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It is certainly possible some system could draw the rail
ratio used in the test  but also quite possible a system
wouldn't.  The key factor here is that one can't just say a
PSU is bad if it doesn't meet an arbitrary test, the PSU has
to meet _it's_ spec and the system integrator is the one
burdened with picking a PSU having right spec for any
particular system.  Plus, I don't think a properly
ventilated system is at 40C, and I don't think the PSU was
rated for 40C.  We know, unfortunately, that most median
grade or lesser PSU are rated only for full load at 25C.

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Being able to pass the test is a good thing, certainly a
sign of a psu more suited for similar load and all else
equal, with more margin and/or better cooling... but it
doesn't necessarily disqualify a PSU from being able to run
a particular system, especially these days with 500W PSU
being quite common but most systems using under 300W.

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