My computer runs Windows XP, has 512 MB of RAM (two 256 MB chips), a CPU
running at 1300 MHZ, and an 80 GB hard drive that is about 20 percent full.

I use Ad-Aware SE Personal for protection against spyware, and AVG Free for
protection against virus attacks. Both of these programs are updated
regularly, and are run several times each week.

I have the latest Microsoft Updates installed. Service Pack 2 is also
installed.

My problem is that when I power up the machine, the boot will often fail
with an error message that tells me the signal was not found. If I power
down, then power back up, the system may boot successfully. However, it
sometimes takes several attempts of powering down, then powering back up
before a successful boot occurs.

The failure of the boot occurs at varying points in the boot process, and
almost never in exactly the same point.

Once I achieve a successful boot, the machine can be left on for days and
never experience a failure of any kind. However, if I power down then the
machine will often (but not always) fail to boot during the next power up.

If anyone has a suggestion as to the cause of the problem, it will be most
welcome.

Thank you.

Papa wrote:

> My computer runs Windows XP, has 512 MB of RAM (two 256 MB chips), a
> CPU running at 1300 MHZ, and an 80 GB hard drive that is about 20
> percent full.
>
> I use Ad-Aware SE Personal for protection against spyware, and AVG
> Free for protection against virus attacks. Both of these programs are
> updated regularly, and are run several times each week.
>
> I have the latest Microsoft Updates installed. Service Pack 2 is also
> installed.
>
> My problem is that when I power up the machine, the boot will often
> fail with an error message that tells me the signal was not found. If
> I power down, then power back up, the system may boot successfully.
> However, it sometimes takes several attempts of powering down, then
> powering back up before a successful boot occurs.
>
> The failure of the boot occurs at varying points in the boot process,
> and almost never in exactly the same point.
>
> Once I achieve a successful boot, the machine can be left on for days
> and never experience a failure of any kind. However, if I power down
> then the machine will often (but not always) fail to boot during the
> next power up.

Although any of the hardware could be failing (and this is definitely a
hardware, not software, problem), this is a classic symptom of a
failing power supply. So I would start by swapping out the psu for a
known-working one and see if that solves the issue. Here are general
hardware troubleshooting steps:

http://www.elephantboycomputers.com/...ardware_Tshoot

Testing hardware failures often involves swapping out suspected parts
with known-good parts. If you can't do the testing yourself and/or are
uncomfortable opening your computer, take the machine to a professional
computer repair shop (not your local equivalent of BigStoreUSA). Have
all your data backed up before you take the machine into a shop.

Malke
--
Elephant Boy Computers
www.elephantboycomputers.com
"Don't Panic!"
MS-MVP Windows - Shell/User

"Malke" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Papa wrote:
>
>> My computer runs Windows XP, has 512 MB of RAM (two 256 MB chips), a
>> CPU running at 1300 MHZ, and an 80 GB hard drive that is about 20
>> percent full.
>>
>> I use Ad-Aware SE Personal for protection against spyware, and AVG
>> Free for protection against virus attacks. Both of these programs are
>> updated regularly, and are run several times each week.
>>
>> I have the latest Microsoft Updates installed. Service Pack 2 is also
>> installed.
>>
>> My problem is that when I power up the machine, the boot will often
>> fail with an error message that tells me the signal was not found. If
>> I power down, then power back up, the system may boot successfully.
>> However, it sometimes takes several attempts of powering down, then
>> powering back up before a successful boot occurs.
>>
>> The failure of the boot occurs at varying points in the boot process,
>> and almost never in exactly the same point.
>>
>> Once I achieve a successful boot, the machine can be left on for days
>> and never experience a failure of any kind. However, if I power down
>> then the machine will often (but not always) fail to boot during the
>> next power up.
>
> Although any of the hardware could be failing (and this is definitely a
> hardware, not software, problem), this is a classic symptom of a
> failing power supply. So I would start by swapping out the psu for a
> known-working one and see if that solves the issue. Here are general
> hardware troubleshooting steps:
>
> http://www.elephantboycomputers.com/...ardware_Tshoot
>
> Testing hardware failures often involves swapping out suspected parts
> with known-good parts. If you can't do the testing yourself and/or are
> uncomfortable opening your computer, take the machine to a professional
> computer repair shop (not your local equivalent of BigStoreUSA). Have
> all your data backed up before you take the machine into a shop.
>
> Malke
> --
> Elephant Boy Computers
> www.elephantboycomputers.com
> "Don't Panic!"
> MS-MVP Windows - Shell/User

Thank you for the help. Much appreciated.

I built this machine a couple of years ago, so I feel comfortable opening
the case to work on it. My first thought was that the problem might be a
flaky memory chip, but the fact that there are no errors once the machine
boots up successfully made me doubt that. Then I wondered if maybe a unique
set of memory addresses or hard drive addresses (the ones used during the
boot) were defective. If that were the case, then perhaps it is a memory or
hard drive problem. On the other hand, I have already defragged and tested
the HD and could not make it fail, so that brings me back to a possibly
defective memory chip.

However, your suggestion that it might be the power supply seems to be more
likely because AFAIK more power is required during the boot up than is
required once the boot up is achieved - and the system never fails once the
boot up successfully completes.

I'll put in a good PS and see what happens. If that doesn't solve it, then
I'll have to start the ole "process of elimination" testing by swapping out
hardware items one at a time.

Thanks again.

Foundation of any computer is its power supply. A marginal or
defective supply will cause failures in other parts - ie memory.
Furthermore, defective or marginal supplies can be detected even before
failures occur. Industry professionals have a simple device as
ubiquitous as a screw driver. Numbers from a 3.5 digit multimeter will
confirm power supply integrity in but minutes - far faster than even
swapping a supply. Furthermore, the replacement supply could also be
marginal - and still requires confirmation with a meter.

In your case, voltages on any one of red, purple, orange, and yellow
wires from power supply to motherboard must exceed 3.23, 4.87, and
11.7. Further information may be obtained by posting those numbers.
Those numbers are best obtained when multitasking programs so that as
many peripherals are being accessed simultaneously.

There is no better testing method without more expensive equipment.
Even power supply testers cannot confirm power supply integrity - the
computer is a superior load for testing.

Before parts were failing, those voltage numbers would have already
been excessively low - symptoms of an impending problem. In fact, that
first power supply may have always been marginal and may have been
detected when system was first built.

Swapping parts to fix anything - also called shotgunning - is a
symptom of unsufficient training. Learning basic concepts means less
time by not repeatedly swapping. Fixing things without first
collecting facts also can complicate a simple solution. Meter will
identify or eliminate power supply 'system' as a reason for failure
(yes, power supply is only one component of a power supply system).
Then one moves on quickly to other suspects. 3.5 digit multimeter is a
tool so ubiquitous even among weekend warriors as to be sold in Radio
Shack, K-mart, Home Depot, Sears, and Lowes. Get the meter because
even a new power supply should be confirmed.

Papa wrote:
> Thank you for the help. Much appreciated.
>
> I built this machine a couple of years ago, so I feel comfortable opening
> the case to work on it. My first thought was that the problem might be a
> flaky memory chip, but the fact that there are no errors once the machine
> boots up successfully made me doubt that. Then I wondered if maybe a unique
> set of memory addresses or hard drive addresses (the ones used during the
> boot) were defective. If that were the case, then perhaps it is a memory or
> hard drive problem. On the other hand, I have already defragged and tested
> the HD and could not make it fail, so that brings me back to a possibly
> defective memory chip.
>
> However, your suggestion that it might be the power supply seems to be more
> likely because AFAIK more power is required during the boot up than is
> required once the boot up is achieved - and the system never fails once the
> boot up successfully completes.
>
> I'll put in a good PS and see what happens. If that doesn't solve it, then
> I'll have to start the ole "process of elimination" testing by swapping out
> hardware items one at a time.

Yes, what you say is obviously true. Thanks for the lecture and have a nice
day.

I apologize for the belated post, but just wanted to let you know that the
problem, as you predicted, was the power supply. Installing a new PS fixed
it, and now there are no more boot-up failures.

Thank you.