Boot Problem With APC Back-UPS ES 725VA

[Michael Taylor]

I purchased, about two weeks ago, a new APC Back-UPS ES 725VA. On cold
and warm boots the computer does not perform the POST. The computer
does not start the POST, it just sits there, the only thing that is
displayed is the small Gateway logo. I have to turn off the computer
and the UPS then power on the UPS afterwards the computer boots and
operates normally. When the computer and monitor is connected to the
protected, non-battery outlets the does the same thing (I assume) and
the monitor enters a low-power state so I can tell what the computer
is doing, but it still does not boot. The computer boots fine when
plugged into the wall outlet, but that defeats the purpose of the UPS.
A USB cable connects the UPS to the CPU. I am running Windows XP Pro.
Could the problem be an incorrect BIOS setting? Any ideas will be
appreciated.

Thanks,
Michael

 

[kony]

I purchased, about two weeks ago, a new APC Back-UPS ES 725VA. On cold
and warm boots the computer does not perform the POST. The computer
does not start the POST, it just sits there, the only thing that is
displayed is the small Gateway logo. I have to turn off the computer
and the UPS then power on the UPS afterwards the computer boots and
operates normally. When the computer and monitor is connected to the
protected, non-battery outlets the does the same thing (I assume) and
the monitor enters a low-power state so I can tell what the computer
is doing, but it still does not boot. The computer boots fine when
plugged into the wall outlet, but that defeats the purpose of the UPS.
A USB cable connects the UPS to the CPU. I am running Windows XP Pro.
Could the problem be an incorrect BIOS setting? Any ideas will be
appreciated.

Thanks,
Michael

There should be no changes (to your computer) necessary to use the
UPS.

If your system behaved the same connected directly to the wall outlet
without the UPS, I would've speculated that the power supply was
either dying or barely insufficient capacity, but so long as you
aren't essentially repeating the (disconnect from AC power) when using
the wall outlet without the UPS, that is, you can keep the PC
connected to the wall outlet and not see the problem, then the UPS is
defective and should be returned.


Dave

 

[CBFalconer]

There should be no changes (to your computer) necessary to use the
UPS.

If your system behaved the same connected directly to the wall outlet
without the UPS, I would've speculated that the power supply was
either dying or barely insufficient capacity, but so long as you
aren't essentially repeating the (disconnect from AC power) when using
the wall outlet without the UPS, that is, you can keep the PC
connected to the wall outlet and not see the problem, then the UPS is
defective and should be returned.

It doesn't necessarily have to be defective to not work, just
generate a different waveform, which pushes the PC supply over the
hump. Many systems generate something closer to a square wave
than a sine, which has a different peak to RMS ratio.

 

[Michael Taylor]

What you suggest sounds like the problem. Is there any way to fix the
irregular waveform? I have read that other users have had similar
problems. Like I said before, the computer boots and operates fine
when plugged into the wall outlet. I have no reason to believe that
the UPS is defective. It is possibly defective, but I doubt it since
the UPS is brand new.

Thanks,
Michael

 

[kony]

It doesn't necessarily have to be defective to not work, just
generate a different waveform, which pushes the PC supply over the
hump. Many systems generate something closer to a square wave
than a sine, which has a different peak to RMS ratio.

I would be considering the design defective then, after all it doen't
work in the intended application.

I had thought the OP mentioned running from the non-battery outlets
though, which should remove the waveform issue, not running through
the DC-AC conversion at all.


Dave

 

[Mike Walsh]

Most UPS boxes just pass through the AC line voltage unless the voltage drops too low, then they switch over to the batteries which can produce anything from a clean signal that is close to a sine wave to a ragged square wave. The problem might have nothing to do with power and could be an intermittent problem with the BIOS not being able to run.

 

[CBFalconer]

What you suggest sounds like the problem. Is there any way to fix
the irregular waveform? I have read that other users have had
similar problems. Like I said before, the computer boots and
operates fine when plugged into the wall outlet. I have no reason
to believe that the UPS is defective. It is possibly defective,
but I doubt it since the UPS is brand new.

Please do not toppost. Please do not send direct replies when
such should be in the newsgroup only.

You can check the waveform with a 'scope. Apart from that, it is
a design decision, and may or may not be spec'd for the UPS. The
most likely culprit remains the PC supply. You may be able to
ease that load by altering the HD spin up sequence and delays.