Power Supply - DOA?

On Sat, 12 Nov 2005 18:44:37 -0800, "Jim" <null.RemoveThis@null.com>
wrote:

>Some mobo's have a safety mechanism that prevents the mobo from booting if
>the CPU fan is not functional! It's intended to save your CPU. So there's
>really no reason not to hook it up. It may also shutdown the mobo if the
>fan runs too slowly.

There is a very good reason not to hook it up- if the fan
doesn't have RPM feedback or it's not supposed to spin fast
and the board isn't calibrated properly for low fan RPMs
(it's VERY common that boards aren't).

Providing the CPU thermal sensing is working properly there
is no real need for a fan failure shutdown, and in fact it
is extremely rare to see a fan failure with a good quality
large fan running at low RPM.
 >> Stay informed about: Power Supply - DOA? 

On Sun, 13 Nov 2005 02:30:20 GMT, no.DeleteThis@spam.invalid (endorice)
wrote:

>I'm putting an Asus P4P800-SE motherboard in an Antec SLK2650-BQE that
>has an Antec SP-350 SmartPower power supply.
>
>When I turned on the machine, the power supply fan doesn't come on.
>I
>get screen display, and make it into the BIOS setup and then the
>system
>just shuts off.

Next time, don't go into the bios setup "yet". Watch the
initial POST screen to see if it shows any alerts for
something like a fan failure notice.

Either way, check the bios for that setting and (at least
temporarily) disable it, as well as disabling any other
similar shutdown alerts.

However, before you do that, make sure your heatsink is
installed properly. If the CPU is overheating it can do
exactly as you report, and turning off a shutdown mechanism
for CPU overheat when it IS overheating could damage it. To
be on the safe side I suggest that you remove the heatsink,
examine the base to see if it looked like it was making good
contact. However, if you do that you may not be able to
reuse the original thermal pad or compound, may need clean
off the original and apply fresh compound. If it is
difficult to clean off, try a petroleum based solvent if
alcohol won't dissolve it.

>In the BIOS screen, I see that my CPU and drive have
>been detected.
>
>I do have the green LED "stand-by" illuminated on the motherboard. I
>have connected the PWR_FAN from the motherboard connected to the leads
>from the power supply.

Disconnect that - do this first and then retry the system.

>I do not yet have a CPU fan installed (thought
>I'd do that after the system boots properly).

What are you thinking here?
You should never have turned on the system without the fan.
It is not subject to your desires whether to do this. It
requires fan cooling, period. It can run for a few dozen
seconds before it begins to get to a point of overheating,
but cycling it on and off does not "reset" that few dozen
seconds unless you allow the 'sink to completely cool
inbetween each. Certainly booting the system and the
resulting state is going to be more than a few dozen
seconds, there was no good reason not to install the fan
already.


>
>Can I safely assume that the power supply is bad, or are there other
>things I should be checking for?

No, there is no reason to suspect the power supply is bad
until after you take voltage readings with a multimeter, and
then if the voltages look out of spec. It is premature to
conclude and not a primary suspect yet.
 >> Stay informed about: Power Supply - DOA? 

You connected power to the power_fan connector on the motherboard?
Good luck with the next board you buy!!


"kony" <spam RemoveThis @spam.com> wrote in message
news:6dddn1de6ajvlqquk30kurkpeh5edrplnr@4ax.com...
> On Sun, 13 Nov 2005 02:30:20 GMT, no RemoveThis @spam.invalid (endorice)
> wrote:
>
>>I'm putting an Asus P4P800-SE motherboard in an Antec SLK2650-BQE that
>>has an Antec SP-350 SmartPower power supply.
>>
>>When I turned on the machine, the power supply fan doesn't come on.
>>I
>>get screen display, and make it into the BIOS setup and then the
>>system
>>just shuts off.
>
> Next time, don't go into the bios setup "yet". Watch the
> initial POST screen to see if it shows any alerts for
> something like a fan failure notice.
>
> Either way, check the bios for that setting and (at least
> temporarily) disable it, as well as disabling any other
> similar shutdown alerts.
>
> However, before you do that, make sure your heatsink is
> installed properly. If the CPU is overheating it can do
> exactly as you report, and turning off a shutdown mechanism
> for CPU overheat when it IS overheating could damage it. To
> be on the safe side I suggest that you remove the heatsink,
> examine the base to see if it looked like it was making good
> contact. However, if you do that you may not be able to
> reuse the original thermal pad or compound, may need clean
> off the original and apply fresh compound. If it is
> difficult to clean off, try a petroleum based solvent if
> alcohol won't dissolve it.
>
>>In the BIOS screen, I see that my CPU and drive have
>>been detected.
>>
>>I do have the green LED "stand-by" illuminated on the motherboard. I
>>have connected the PWR_FAN from the motherboard connected to the leads
>>from the power supply.
>
> Disconnect that - do this first and then retry the system.
>
>>I do not yet have a CPU fan installed (thought
>>I'd do that after the system boots properly).
>
> What are you thinking here?
> You should never have turned on the system without the fan.
> It is not subject to your desires whether to do this. It
> requires fan cooling, period. It can run for a few dozen
> seconds before it begins to get to a point of overheating,
> but cycling it on and off does not "reset" that few dozen
> seconds unless you allow the 'sink to completely cool
> inbetween each. Certainly booting the system and the
> resulting state is going to be more than a few dozen
> seconds, there was no good reason not to install the fan
> already.
>
>
>>
>>Can I safely assume that the power supply is bad, or are there other
>>things I should be checking for?
>
> No, there is no reason to suspect the power supply is bad
> until after you take voltage readings with a multimeter, and
> then if the voltages look out of spec. It is premature to
> conclude and not a primary suspect yet.
 >> Stay informed about: Power Supply - DOA? 

"kony" <spam RemoveThis @spam.com> wrote in message
news:39ddn1hhjiusjvtnci57l2ppjtp713vs2s@4ax.com...
> On Sat, 12 Nov 2005 18:44:37 -0800, "Jim" <null RemoveThis @null.com>
> wrote:
>
> >Some mobo's have a safety mechanism that prevents the mobo from booting
if
> >the CPU fan is not functional! It's intended to save your CPU. So
there's
> >really no reason not to hook it up. It may also shutdown the mobo if the
> >fan runs too slowly.
>
> There is a very good reason not to hook it up- if the fan
> doesn't have RPM feedback or it's not supposed to spin fast
> and the board isn't calibrated properly for low fan RPMs
> (it's VERY common that boards aren't).
>

If you install *some* CPUs without a fan, you'll KILL the CPU in seconds!
The AMD Athlon was/is notorious for this, so much so the manfacturer voids
the warranty if you fail to do so. The probability that the fan isn't
calibrated correctly seems remote, to me. And so what if it is, the fact
remains you typically want (if not need) a running fan. The fact it may or
may not be running "to spec" is moot. The issue here is, there's no good
reason to not have the CPU fan running, and a darn good chance if you don't,
you'll damage the CPU.

Jim


> Providing the CPU thermal sensing is working properly there
> is no real need for a fan failure shutdown, and in fact it
> is extremely rare to see a fan failure with a good quality
> large fan running at low RPM.
 >> Stay informed about: Power Supply - DOA? 

> If you install *some* CPUs without a fan, you'll KILL the CPU in seconds!
> The AMD Athlon was/is notorious for this, so much so the manfacturer voids
> the warranty if you fail to do so.


Maybe without a fan AND heatsink, yes. With a heatsink the system would last
at least a minute, even with the hot-headed Thunderbird. So there is no way
that the CPU is getting too hot in the 5-10 seconds before post. Also, if
the MB was powering the system down due to thermal or fan failure you would
get some type of beep code or BIOS message.


For the OP - If the PS fan doesn't spin up when you turn the system on it's
defective, return it.
--


"I don't cheat to survive. I cheat to LIVE!!"
- Alceryes





"Jim" <null.RemoveThis@null.com> wrote in message news:qLydf.312$MN.232@fed1read07...
>
> "kony" <spam.RemoveThis@spam.com> wrote in message
> news:39ddn1hhjiusjvtnci57l2ppjtp713vs2s@4ax.com...
>> On Sat, 12 Nov 2005 18:44:37 -0800, "Jim" <null.RemoveThis@null.com>
>> wrote:
>>
>> >Some mobo's have a safety mechanism that prevents the mobo from booting
> if
>> >the CPU fan is not functional! It's intended to save your CPU. So
> there's
>> >really no reason not to hook it up. It may also shutdown the mobo if
>> >the
>> >fan runs too slowly.
>>
>> There is a very good reason not to hook it up- if the fan
>> doesn't have RPM feedback or it's not supposed to spin fast
>> and the board isn't calibrated properly for low fan RPMs
>> (it's VERY common that boards aren't).
>>
>
> If you install *some* CPUs without a fan, you'll KILL the CPU in seconds!
> The AMD Athlon was/is notorious for this, so much so the manfacturer voids
> the warranty if you fail to do so. The probability that the fan isn't
> calibrated correctly seems remote, to me. And so what if it is, the fact
> remains you typically want (if not need) a running fan. The fact it may
> or
> may not be running "to spec" is moot. The issue here is, there's no good
> reason to not have the CPU fan running, and a darn good chance if you
> don't,
> you'll damage the CPU.
>
> Jim
>
>
>> Providing the CPU thermal sensing is working properly there
>> is no real need for a fan failure shutdown, and in fact it
>> is extremely rare to see a fan failure with a good quality
>> large fan running at low RPM.
>
>
 >> Stay informed about: Power Supply - DOA? 

On Sun, 13 Nov 2005 14:46:54 GMT, "Alceryes"
<replytopost DeleteThis @thankyou.com> wrote:


>For the OP - If the PS fan doesn't spin up when you turn the system on it's
>defective, return it.

Some Antecs have a fan control and noise reduction feature
that does allow fan to not spin until it gets hotter. It
can matter if it's plugged into a motherboard PSU fan header
(or another fan header) or not.
 >> Stay informed about: Power Supply - DOA? 

> Some Antecs have a fan control and noise reduction feature
> that does allow fan to not spin until it gets hotter. It


Yes, but I think these power supply fans at least spin up when first powered
on and then stop once the thermistor reading kicks in. That way if you have
a failure at least you have the fan running instead of stopping (and most
likely taking the PS with it).
--


"I don't cheat to survive. I cheat to LIVE!!"
- Alceryes


"kony" <spam DeleteThis @spam.com> wrote in message
news:tvsen153fu1rnka4t9r786i1kv1vp1ai39@4ax.com...
> On Sun, 13 Nov 2005 14:46:54 GMT, "Alceryes"
> <replytopost DeleteThis @thankyou.com> wrote:
>
>
>>For the OP - If the PS fan doesn't spin up when you turn the system on
>>it's
>>defective, return it.
>
> Some Antecs have a fan control and noise reduction feature
> that does allow fan to not spin until it gets hotter. It
> can matter if it's plugged into a motherboard PSU fan header
> (or another fan header) or not.
 >> Stay informed about: Power Supply - DOA? 

Thanks to everyone who contributed suggestions for me, much
appreciated!

> Some mobo's have a safety mechanism that prevents the mobo from
booting if the CPU fan is not functional! It's intended to save your
CPU. So there's
> really no reason not to hook it up. It may also shutdown the mobo if
the
> fan runs too slowly.
Well, that's exactly what the problem was. I was transferring this
CPU from a Dell 4600, which had a heat sink, but no CPU fan. I
thought I could boot the machine, confirm everything was working OK
(run for a minute) and then I was going to hook up the CPU fan.
Turns out that this Asus motherboard required the CPU fan to be
hooked up before booting (althought it's not specifically mentioned
in the manual).

> You connected power to the power_fan connector on the motherboard?
Good luck with the next board you buy!!
OK - I don't follow. My motherboard has a 3 pin PWR_FAN connector. I
*assumed* I was supposed to take the female connector that came out of
the power supply, and hook to the male connector on the MB. Am I
wrong about that?

Anyhow, I just hooked up the CPU fan, and now I'm booting into safe
mode and running windows. I have a couple of BIOS warnings about
overclock settings not being correct which I'll look at later.

Thanks again for all of your suggestions!
 >> Stay informed about: Power Supply - DOA?