s5393 power up

i am having trouble getting the s5393 tempest i5400pl to power up.
when you turn it on it will spin the fans for a few seconds then shut
off. sometimes it boots fine. it does not reliably power up. is anyone
having this problem??

In article <aa98009a-5936-43f2-83f8->,
jim <> wrote:
>i am having trouble getting the s5393 tempest i5400pl to power up.
>when you turn it on it will spin the fans for a few seconds then shut
>off. sometimes it boots fine. it does not reliably power up. is anyone
>having this problem??

How are the CPU fans?
--
Member - Liberal International
This is Ici
God, Queen and country! Beware Anti-Christ rising!
USA petition for dissolution of your nation!

On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>
> jim <jimeric...@gmail.com> wrote:
> >i am having trouble getting the s5393 tempest i5400pl to power up.
> >when you turn it on it will spin the fans for a few seconds then shut
> >off. sometimes it boots fine. it does not reliably power up. is anyone
> >having this problem??
>
> How are the CPU fans?
> --
> Member - Liberal International
> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> God, Queen and country! Beware Anti-Christ rising!
> USA petition for dissolution of your nation!

they spin with the other fans for a few seconds. they also run fine if
it decides to boot. i have already had two different psu on it so i
don't think its that.

In article <125f3fd6-5e3c-459a-99b9->,
jim <> wrote:
>On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>>
>> jim <jimeric...@gmail.com> wrote:
>> >i am having trouble getting the s5393 tempest i5400pl to power up.
>> >when you turn it on it will spin the fans for a few seconds then shut
>> >off. sometimes it boots fine. it does not reliably power up. is anyone
>> >having this problem??
>>
>> How are the CPU fans?
>> --
>> Member - Liberal International
>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
>> God, Queen and country! Beware Anti-Christ rising!
>> USA petition for dissolution of your nation!
>
>they spin with the other fans for a few seconds. they also run fine if
>it decides to boot. i have already had two different psu on it so i
>don't think its that.

I know what 2 CPU heatsinks and fans were not working on my S2727 the
MB would shut down right away because the feedback was incorrect.
--
Member - Liberal International
This is Ici
God, Queen and country! Beware Anti-Christ rising!
USA petition for dissolution of your nation!

On Jun 10, 11:22 am, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
> In article <125f3fd6-5e3c-459a-99b9-d17bf77da...@m3g2000hsc.googlegroups.com>,
>
>
>
> jim <jimeric...@gmail.com> wrote:
> >On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
> >> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>
> >> jim <jimeric...@gmail.com> wrote:
> >> >i am having trouble getting the s5393 tempest i5400pl to power up.
> >> >when you turn it on it will spin the fans for a few seconds then shut
> >> >off. sometimes it boots fine. it does not reliably power up. is anyone
> >> >having this problem??
>
> >> How are the CPU fans?
> >> --
> >> Member - Liberal International
> >> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> >> God, Queen and country! Beware Anti-Christ rising!
> >> USA petition for dissolution of your nation!
>
> >they spin with the other fans for a few seconds. they also run fine if
> >it decides to boot. i have already had two different psu on it so i
> >don't think its that.
>
> I know what 2 CPU heatsinks and fans were not working on my S2727 the
> MB would shut down right away because the feedback was incorrect.
> --
> Member - Liberal International
> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> God, Queen and country! Beware Anti-Christ rising!
> USA petition for dissolution of your nation!

hmm, i wonder... i have been getting a message about the "cmos
checksum is wrong using default configuration" when it does happen to
boot. could this have something to do with it?? what exactly is the
cmos checksum??

On Jun 11, 11:43 am, jim <jimeric...@gmail.com> wrote:
> On Jun 10, 11:22 am, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>
>
>
> > In article <125f3fd6-5e3c-459a-99b9-d17bf77da...@m3g2000hsc.googlegroups.com>,
>
> > jim <jimeric...@gmail.com> wrote:
> > >On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
> > >> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>
> > >> jim <jimeric...@gmail.com> wrote:
> > >> >i am having trouble getting the s5393 tempest i5400pl to power up.
> > >> >when you turn it on it will spin the fans for a few seconds then shut
> > >> >off. sometimes it boots fine. it does not reliably power up. is anyone
> > >> >having this problem??
>
> > >> How are the CPU fans?
> > >> --
> > >> Member - Liberal International
> > >> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> > >> God, Queen and country! Beware Anti-Christ rising!
> > >> USA petition for dissolution of your nation!
>
> > >they spin with the other fans for a few seconds. they also run fine if
> > >it decides to boot. i have already had two different psu on it so i
> > >don't think its that.
>
> > I know what 2 CPU heatsinks and fans were not working on my S2727 the
> > MB would shut down right away because the feedback was incorrect.
> > --
> > Member - Liberal International
> > This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> > God, Queen and country! Beware Anti-Christ rising!
> > USA petition for dissolution of your nation!
>
> hmm, i wonder... i have been getting a message about the "cmos
> checksum is wrong using default configuration" when it does happen to
> boot. could this have something to do with it?? what exactly is the
> cmos checksum??

CMOS is a chip manufacturing technology that requires very low power;
consequently it is well suited to retain setup information about your
mainboard and peripherals, the power normally coming from a lithium
battery on the motherboard. The message may be an indication that the
CMOS battery is getting old and weak (don't laugh, you will be too
someday.) So there may be an option in the BIOS to restore CMOS
default settings. This may help. And it may be worthwhile to check the
battery voltage. If you take the battery out of the motherboard to
check it, power to the CMOS will fail and you will need to deal with
restoring the values. So I suggest trying the restore settings BIOS
option first, you'll need to know this method anyway if you pop the
battery out. Batteries are pretty cheap and usually last a long time.
It is possible, though I don't know how likely, that some other
component is bleeding the battery down, but this is a fairly involved
issue if present - try the cheap fix first.

Dave

midol wrote:
> On Jun 11, 11:43 am, jim <jimeric...@gmail.com> wrote:
>> On Jun 10, 11:22 am, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>>
>>
>>
>>> In article <125f3fd6-5e3c-459a-99b9-d17bf77da...@m3g2000hsc.googlegroups.com>,
>>> jim <jimeric...@gmail.com> wrote:
>>>> On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>>>>> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>>>>> jim <jimeric...@gmail.com> wrote:
>>>>>> i am having trouble getting the s5393 tempest i5400pl to power up.
>>>>>> when you turn it on it will spin the fans for a few seconds then shut
>>>>>> off. sometimes it boots fine. it does not reliably power up. is anyone
>>>>>> having this problem??
>>>>> How are the CPU fans?
>>>>> --
>>>>> Member - Liberal International
>>>>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
>>>>> God, Queen and country! Beware Anti-Christ rising!
>>>>> USA petition for dissolution of your nation!
>>>> they spin with the other fans for a few seconds. they also run fine if
>>>> it decides to boot. i have already had two different psu on it so i
>>>> don't think its that.
>>> I know what 2 CPU heatsinks and fans were not working on my S2727 the
>>> MB would shut down right away because the feedback was incorrect.
>>> --
>>> Member - Liberal International
>>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
>>> God, Queen and country! Beware Anti-Christ rising!
>>> USA petition for dissolution of your nation!
>> hmm, i wonder... i have been getting a message about the "cmos
>> checksum is wrong using default configuration" when it does happen to
>> boot. could this have something to do with it?? what exactly is the
>> cmos checksum??
>
> CMOS is a chip manufacturing technology that requires very low power;
> consequently it is well suited to retain setup information about your
> mainboard and peripherals, the power normally coming from a lithium
> battery on the motherboard. The message may be an indication that the
> CMOS battery is getting old and weak (don't laugh, you will be too
> someday.) So there may be an option in the BIOS to restore CMOS
> default settings. This may help. And it may be worthwhile to check the
> battery voltage. If you take the battery out of the motherboard to
> check it, power to the CMOS will fail and you will need to deal with
> restoring the values. So I suggest trying the restore settings BIOS
> option first, you'll need to know this method anyway if you pop the
> battery out. Batteries are pretty cheap and usually last a long time.
> It is possible, though I don't know how likely, that some other
> component is bleeding the battery down, but this is a fairly involved
> issue if present - try the cheap fix first.
>
> Dave

The CMOS RAM is housed in the Southbridge chip. It is powered from a
separate rail on the Southbridge chip, and special isolation techniques
are used between the area where the CMOS and RTC (real time clock)
are located. That cuts down on leakage, when the rest of the computer
is not powered. (It is referred to as the "CMOS well", because it
can be at a different potential than the rest of the Southbridge chip.)

The CMOS RAM runs from the logical ORing of the battery and a voltage
made from +5VSB. If you regularly turn off the computer at the back
of the machine every day (i.e. the switch on the PSU is switched off),
then the CMOS battery (likely a CR2032) is called on to power the
CMOS and RTC. (Check the manual or look at the battery itself, to
verify it is a CR2032. Years ago, there were more different battery
formats used.)

http://www.radioshack.com/product/in...ductId=2062105

If you leave a computer unpowered (switched off at the back or unplugged),
a CR2032 lasts about 3 years. If +5VSB is available all the time (such
as what happens if the computer is left in suspend to RAM), then the
battery can last for its shelf life, perhaps 10 years. In other words, if
+5VSB is available, the battery is not supposed to be used at all. All
the microamps come from a linear regulator tied to +5VSB.

The Southbridge has a minimum voltage spec, for continued operation of
the CMOS area. Say it is 2.0 volts, for example. The battery is connected
to the Southbridge via a Schottky diode, which wastes another 0.4V
at the tiny current flow level involved. (The diode prevents accidental
attempts to recharge the battery, which could cause it to burst.) So
the minimum battery voltage might be 2.4V, to have the thing continue to
remember the CMOS settings while the power is off. New batteries likely
read 3.0V or higher. A multimeter can be used to check the voltage
level, and no artificial loading is needed to evaluate the battery.

When the BIOS starts up, it computes the checksum of the info in the
CMOS RAM, as a mechanism to detect corruption. It is possible the
password field in the CMOS, is protected by its own checksum. Simple
checksums are what the BIOS uses, to judge the contents of the CMOS
RAM.

http://www.bioscentral.com/misc/cmosmap.htm

Some users have claimed, that if you pull the old battery, and install
the new one without a lot of fumbling about, that the settings can be
maintained. It all depends on whether there are any capacitors present,
which hold a small amount of charge, while you're changing the battery.
It helps to have a paper list handy, with any custom settings that
are needed to get the machine to boot, for occasions where the
settings are lost, and default settings are being used. Alternately,
a series of digital camera photos of the BIOS screens, can be used
as a reference for later (if you store the pictures on another
computer).

Since the machine seemed to run, while using the defaults, it could
be that there are no custom settings being used at all. Normally,
something like the boot order, would have to be restored in the
BIOS setup screens, to get any work done.

Paul

On Jun 11, 4:00 pm, Paul <nos...@needed.com> wrote:
> midol wrote:
> > On Jun 11, 11:43 am, jim <jimeric...@gmail.com> wrote:
> >> On Jun 10, 11:22 am, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>
> >>> In article <125f3fd6-5e3c-459a-99b9-d17bf77da...@m3g2000hsc.googlegroups.com>,
> >>> jim <jimeric...@gmail.com> wrote:
> >>>> On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
> >>>>> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
> >>>>> jim <jimeric...@gmail.com> wrote:
> >>>>>> i am having trouble getting the s5393 tempest i5400pl to power up.
> >>>>>> when you turn it on it will spin the fans for a few seconds then shut
> >>>>>> off. sometimes it boots fine. it does not reliably power up. is anyone
> >>>>>> having this problem??
> >>>>> How are the CPU fans?
> >>>>> --
> >>>>> Member - Liberal International
> >>>>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> >>>>> God, Queen and country! Beware Anti-Christ rising!
> >>>>> USA petition for dissolution of your nation!
> >>>> they spin with the other fans for a few seconds. they also run fine if
> >>>> it decides to boot. i have already had two different psu on it so i
> >>>> don't think its that.
> >>> I know what 2 CPU heatsinks and fans were not working on my S2727 the
> >>> MB would shut down right away because the feedback was incorrect.
> >>> --
> >>> Member - Liberal International
> >>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
> >>> God, Queen and country! Beware Anti-Christ rising!
> >>> USA petition for dissolution of your nation!
> >> hmm, i wonder... i have been getting a message about the "cmos
> >> checksum is wrong using default configuration" when it does happen to
> >> boot. could this have something to do with it?? what exactly is the
> >> cmos checksum??
>
> > CMOS is a chip manufacturing technology that requires very low power;
> > consequently it is well suited to retain setup information about your
> > mainboard and peripherals, the power normally coming from a lithium
> > battery on the motherboard. The message may be an indication that the
> > CMOS battery is getting old and weak (don't laugh, you will be too
> > someday.) So there may be an option in the BIOS to restore CMOS
> > default settings. This may help. And it may be worthwhile to check the
> > battery voltage. If you take the battery out of the motherboard to
> > check it, power to the CMOS will fail and you will need to deal with
> > restoring the values. So I suggest trying the restore settings BIOS
> > option first, you'll need to know this method anyway if you pop the
> > battery out. Batteries are pretty cheap and usually last a long time.
> > It is possible, though I don't know how likely, that some other
> > component is bleeding the battery down, but this is a fairly involved
> > issue if present - try the cheap fix first.
>
> > Dave
>
> The CMOS RAM is housed in the Southbridge chip. It is powered from a
> separate rail on the Southbridge chip, and special isolation techniques
> are used between the area where the CMOS and RTC (real time clock)
> are located. That cuts down on leakage, when the rest of the computer
> is not powered. (It is referred to as the "CMOS well", because it
> can be at a different potential than the rest of the Southbridge chip.)
>
> The CMOS RAM runs from the logical ORing of the battery and a voltage
> made from +5VSB. If you regularly turn off the computer at the back
> of the machine every day (i.e. the switch on the PSU is switched off),
> then the CMOS battery (likely a CR2032) is called on to power the
> CMOS and RTC. (Check the manual or look at the battery itself, to
> verify it is a CR2032. Years ago, there were more different battery
> formats used.)
>
> http://www.radioshack.com/product/in...ductId=2062105
>
> If you leave a computer unpowered (switched off at the back or unplugged),
> a CR2032 lasts about 3 years. If +5VSB is available all the time (such
> as what happens if the computer is left in suspend to RAM), then the
> battery can last for its shelf life, perhaps 10 years. In other words, if
> +5VSB is available, the battery is not supposed to be used at all. All
> the microamps come from a linear regulator tied to +5VSB.
>
> The Southbridge has a minimum voltage spec, for continued operation of
> the CMOS area. Say it is 2.0 volts, for example. The battery is connected
> to the Southbridge via a Schottky diode, which wastes another 0.4V
> at the tiny current flow level involved. (The diode prevents accidental
> attempts to recharge the battery, which could cause it to burst.) So
> the minimum battery voltage might be 2.4V, to have the thing continue to
> remember the CMOS settings while the power is off. New batteries likely
> read 3.0V or higher. A multimeter can be used to check the voltage
> level, and no artificial loading is needed to evaluate the battery.
>
> When the BIOS starts up, it computes the checksum of the info in the
> CMOS RAM, as a mechanism to detect corruption. It is possible the
> password field in the CMOS, is protected by its own checksum. Simple
> checksums are what the BIOS uses, to judge the contents of the CMOS
> RAM.
>
> http://www.bioscentral.com/misc/cmosmap.htm
>
> Some users have claimed, that if you pull the old battery, and install
> the new one without a lot of fumbling about, that the settings can be
> maintained. It all depends on whether there are any capacitors present,
> which hold a small amount of charge, while you're changing the battery.
> It helps to have a paper list handy, with any custom settings that
> are needed to get the machine to boot, for occasions where the
> settings are lost, and default settings are being used. Alternately,
> a series of digital camera photos of the BIOS screens, can be used
> as a reference for later (if you store the pictures on another
> computer).
>
> Since the machine seemed to run, while using the defaults, it could
> be that there are no custom settings being used at all. Normally,
> something like the boot order, would have to be restored in the
> BIOS setup screens, to get any work done.
>
> Paul

so is it possible i have had two bad psu on it?? the third one should
arrive in a few days. it is a 1200watt thermaltake W0133RU that is
eps12v compliant. any thoughts??

jim wrote:
> On Jun 11, 4:00 pm, Paul <nos...@needed.com> wrote:
>> midol wrote:
>>> On Jun 11, 11:43 am, jim <jimeric...@gmail.com> wrote:
>>>> On Jun 10, 11:22 am, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>>>>> In article <125f3fd6-5e3c-459a-99b9-d17bf77da...@m3g2000hsc.googlegroups.com>,
>>>>> jim <jimeric...@gmail.com> wrote:
>>>>>> On Jun 9, 6:36 pm, doc...@doctor.nl2k.ab.ca (The Doctor) wrote:
>>>>>>> In article <aa98009a-5936-43f2-83f8-624055b80...@25g2000hsx.googlegroups.com>,
>>>>>>> jim <jimeric...@gmail.com> wrote:
>>>>>>>> i am having trouble getting the s5393 tempest i5400pl to power up.
>>>>>>>> when you turn it on it will spin the fans for a few seconds then shut
>>>>>>>> off. sometimes it boots fine. it does not reliably power up. is anyone
>>>>>>>> having this problem??
>>>>>>> How are the CPU fans?
>>>>>>> --
>>>>>>> Member - Liberal International
>>>>>>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
>>>>>>> God, Queen and country! Beware Anti-Christ rising!
>>>>>>> USA petition for dissolution of your nation!
>>>>>> they spin with the other fans for a few seconds. they also run fine if
>>>>>> it decides to boot. i have already had two different psu on it so i
>>>>>> don't think its that.
>>>>> I know what 2 CPU heatsinks and fans were not working on my S2727 the
>>>>> MB would shut down right away because the feedback was incorrect.
>>>>> --
>>>>> Member - Liberal International
>>>>> This is doc...@nl2k.ab.ca Ici doc...@nl2k.ab.ca
>>>>> God, Queen and country! Beware Anti-Christ rising!
>>>>> USA petition for dissolution of your nation!
>>>> hmm, i wonder... i have been getting a message about the "cmos
>>>> checksum is wrong using default configuration" when it does happen to
>>>> boot. could this have something to do with it?? what exactly is the
>>>> cmos checksum??
>>> CMOS is a chip manufacturing technology that requires very low power;
>>> consequently it is well suited to retain setup information about your
>>> mainboard and peripherals, the power normally coming from a lithium
>>> battery on the motherboard. The message may be an indication that the
>>> CMOS battery is getting old and weak (don't laugh, you will be too
>>> someday.) So there may be an option in the BIOS to restore CMOS
>>> default settings. This may help. And it may be worthwhile to check the
>>> battery voltage. If you take the battery out of the motherboard to
>>> check it, power to the CMOS will fail and you will need to deal with
>>> restoring the values. So I suggest trying the restore settings BIOS
>>> option first, you'll need to know this method anyway if you pop the
>>> battery out. Batteries are pretty cheap and usually last a long time.
>>> It is possible, though I don't know how likely, that some other
>>> component is bleeding the battery down, but this is a fairly involved
>>> issue if present - try the cheap fix first.
>>> Dave
>> The CMOS RAM is housed in the Southbridge chip. It is powered from a
>> separate rail on the Southbridge chip, and special isolation techniques
>> are used between the area where the CMOS and RTC (real time clock)
>> are located. That cuts down on leakage, when the rest of the computer
>> is not powered. (It is referred to as the "CMOS well", because it
>> can be at a different potential than the rest of the Southbridge chip.)
>>
>> The CMOS RAM runs from the logical ORing of the battery and a voltage
>> made from +5VSB. If you regularly turn off the computer at the back
>> of the machine every day (i.e. the switch on the PSU is switched off),
>> then the CMOS battery (likely a CR2032) is called on to power the
>> CMOS and RTC. (Check the manual or look at the battery itself, to
>> verify it is a CR2032. Years ago, there were more different battery
>> formats used.)
>>
>> http://www.radioshack.com/product/in...ductId=2062105
>>
>> If you leave a computer unpowered (switched off at the back or unplugged),
>> a CR2032 lasts about 3 years. If +5VSB is available all the time (such
>> as what happens if the computer is left in suspend to RAM), then the
>> battery can last for its shelf life, perhaps 10 years. In other words, if
>> +5VSB is available, the battery is not supposed to be used at all. All
>> the microamps come from a linear regulator tied to +5VSB.
>>
>> The Southbridge has a minimum voltage spec, for continued operation of
>> the CMOS area. Say it is 2.0 volts, for example. The battery is connected
>> to the Southbridge via a Schottky diode, which wastes another 0.4V
>> at the tiny current flow level involved. (The diode prevents accidental
>> attempts to recharge the battery, which could cause it to burst.) So
>> the minimum battery voltage might be 2.4V, to have the thing continue to
>> remember the CMOS settings while the power is off. New batteries likely
>> read 3.0V or higher. A multimeter can be used to check the voltage
>> level, and no artificial loading is needed to evaluate the battery.
>>
>> When the BIOS starts up, it computes the checksum of the info in the
>> CMOS RAM, as a mechanism to detect corruption. It is possible the
>> password field in the CMOS, is protected by its own checksum. Simple
>> checksums are what the BIOS uses, to judge the contents of the CMOS
>> RAM.
>>
>> http://www.bioscentral.com/misc/cmosmap.htm
>>
>> Some users have claimed, that if you pull the old battery, and install
>> the new one without a lot of fumbling about, that the settings can be
>> maintained. It all depends on whether there are any capacitors present,
>> which hold a small amount of charge, while you're changing the battery.
>> It helps to have a paper list handy, with any custom settings that
>> are needed to get the machine to boot, for occasions where the
>> settings are lost, and default settings are being used. Alternately,
>> a series of digital camera photos of the BIOS screens, can be used
>> as a reference for later (if you store the pictures on another
>> computer).
>>
>> Since the machine seemed to run, while using the defaults, it could
>> be that there are no custom settings being used at all. Normally,
>> something like the boot order, would have to be restored in the
>> BIOS setup screens, to get any work done.
>>
>> Paul
>
> so is it possible i have had two bad psu on it?? the third one should
> arrive in a few days. it is a 1200watt thermaltake W0133RU that is
> eps12v compliant. any thoughts??

The power supply itself, will not run unless +5VSB is functional. +5VSB
is also the backup power source for the CMOS. The CR2032 and the
+5VSB sourced sustaining voltage, power the CMOS. For the CMOS to
entirely lose it settings, and for there to be a checksum complaint
for the CMOS, you need a bad CR2032 battery, and also to have shut
off the power supply completely.

The BIOS code in its EEPROM, is also protected by a checksum, but
the error message should be different, if that was the problem. A BIOS
checksum failure can be caused by accidental overclocking of the LPC
clock used with the LPC bus to the EEPROM. (Trying to read bytes from
the EEPROM, before they've settled.)

I don't have enough information, to tell you what exactly is up with
your original symptoms. The power supply itself has protection, and
some of the high end ones have more protection features than the cheap
stuff. Protection on the power supply, should start to be applied, about
35 to 50 milliseconds after the power supply starts - that gives time
for it to stabilize. After that, the power supply may be able to detect
a problem with current draw. Or, the power supply could have a failure
condition internally, leading to it shutting off. (Like rectifier
overtemperature or overcurrent detection.)

If the power supply shuts off, at least some of them have a latch-off
feature. They won't recover, until you flip the switch on the back, to
the off position, and then back to the on position.

Motherboards also have sophisticated protections. The Vcore regulator has
an overcurrent protection feature, and it too can be designed with
latch-off as a feature. Pressing the power button on the front of the
computer case, may not be enough to re-cycle the power, and it might
still need to be shut off at the back, to recover.

If the BIOS detects a CPU fan with no RPM signal, that can be a reason
for shutoff. That usually takes a few seconds. The BIOS tells the
motherboard to shut off the power in that case.

The time constant of the shutoff, can sometimes shed some light on the
failure mechanism. For example, if pressing the power button on the
front of the computer, only elicits a "twitch" from the CPU fan, then
you know that is just enough time for the 35 to 50 millisecond interval
on the power supply to have passed - then you know the power supply
is what detected the problem. As the interval gets longer, things like
motherboard or CPU temperature (THERMTRIP) issues, could be at fault.

The ones that are hard to figure out, involve the inability of a
new motherboard, to reliably detect initial power up. Sometimes, a
source of leakage current (like down the monitor cable), prevents the
motherboard power monitoring circuits, from properly determining that
the board is off. Then, when the power button is pressed on the
front of the computer, it won't start up properly. You can experiment with
the reset button, but I have at least one motherboard in my
possession, that chooses to ignore the reset button, whenever it
gets into a foul mood. (And *no* chip should ignore reset. That was
a shooting offense at the place I used to work. A design should *always*
be resettable.)

With so many different ways for a motherboard to fail to initialize properly,
you can't always isolate the source of the problem to one exact thing.
For example, there were cases in the past, where certain Antec power
supplies, mixed with some Asus motherboards, resulted in problems.
And yet, if the components were mixed with others, perhaps they'd
be perfectly happy. That one seemed to be related to a timing problem,
like the power supply being too slow to get started.

It could always be a motherboard problem - in which case you want to
find a private forum with enough feedback on the product, to see whether
there is a known issue or not. For server motherboards, the best place
I know of is forums.2cpu.com . The reviews on Newegg, are good for
detecting problems with desktop motherboards, but for a server
motherboard, it is harder to find enough customer reviews, to get
a clear picture.

http://forums.2cpu.com/showthread.php?t=90884

Paul