Computer will not boot

  • Thread starter Thread starter Kaelin
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Kaelin

Hi the computer im trying to fix will not boot up -
I press the power button and the speakers make a beep the fans spin
for 1-2 seconds then they stop spinning - the hard drive does not
start spinning the light on the mobo stays on - it does not boot to
bios nothing appears on the moniter not sure if its a bad mobo pcu or
what lemme know what you think.
Justin Miller
 
Kaelin said:
Hi the computer im trying to fix will not boot up -
I press the power button and the speakers make a beep the fans spin
for 1-2 seconds then they stop spinning - the hard drive does not
start spinning the light on the mobo stays on - it does not boot to
bios nothing appears on the moniter not sure if its a bad mobo pcu or
what lemme know what you think.
Justin Miller
Click to expand...

That could be due to a bad power supply, overheating CPU,
a power cable short somewhere, etc. You should disconnect
all data and power cables from the motherboard and
drive, etc. All you should have attached to begin with is
the CPU, RAM and power supply.

What CPU make and model is it?
 
Answer was posted in this newsgroup
alt.comp.hardware.pc-homebuilt as "ATX power problems??" on 1
Mar 2005. Do not wildly disconnect things as if that will
find a problem or make electrons visible. The power supply
'system' can be analyzed in but 2 minutes. Do not assume just
because something illuminates or spin means the power supply
'system' is working. Without those numbers, no one can say
what is and is not working.

In your case, important data is observed on the 3.3, 5,
5VSB, 12 volt, Power Good and Power On signals (red orange
yellow purple green and purple wires) in first 2 seconds as
power switch is pressed. If those numbers still leave you
confused, well, you have obtained numbers which empower the
technically informed. No numbers means your only responses
will be wild speculation. Previously cited were hyperlinks
for further information: "Computer doesnt start at all" in
alt.comp.hardware on 10 Jan 2004 at
http://tinyurl.com/2t69q and
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

Based upon provided symptoms, then literally any component
in that computer could be reason for the failure - including
metal standoffs. Just another reason the fastest solution
begins with the meter.
 
w_tom said:
Answer was posted in this newsgroup
alt.comp.hardware.pc-homebuilt as "ATX power problems??" on 1
Mar 2005. Do not wildly disconnect things as if that will
find a problem or make electrons visible. The power supply
'system' can be analyzed in but 2 minutes. Do not assume just
because something illuminates or spin means the power supply
'system' is working. Without those numbers, no one can say
what is and is not working.

In your case, important data is observed on the 3.3, 5,
5VSB, 12 volt, Power Good and Power On signals (red orange
yellow purple green and purple wires) in first 2 seconds as
power switch is pressed. If those numbers still leave you
confused, well, you have obtained numbers which empower the
technically informed. No numbers means your only responses
will be wild speculation. Previously cited were hyperlinks
for further information: "Computer doesnt start at all" in
alt.comp.hardware on 10 Jan 2004 at
http://tinyurl.com/2t69q and
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9

Based upon provided symptoms, then literally any component
in that computer could be reason for the failure - including
metal standoffs. Just another reason the fastest solution
begins with the meter.
Click to expand...
Or it could simply be that the mobo isn't detecting the CPU fan (either
because the speed sensing on the fan is bust or the fan is plugged into the
wrong header on the mobo).
Therefore I would simply try another fan on the HSF - and no flipping 3 and
a bit digital multimeter required!

SteveH
 
Don't forget to suspect a bad keyboard. And the network
card can be shorted. And line voltage is too low. And some
metal fragment is shorting the motherboard. And the power
switch is internally stuck. Its called 'wildly speculating'.
Yes the 'what it can be' solution means he must replace
everything until he found the one real problem or until the
stray short just fell out. Its called shotgunning. Costs
more money. Takes more time. Sometimes only fixes the
symptom rather than the problem.

If your car mechanic used shotgunning, then we would call it
a scam. Get the meter. Identify the problem in two minutes.
Any other solution is simply trying to do things harder - not
smarter. The fan as a possible reason - wild speculation -
shotgunning.
 
w_tom said:
Don't forget to suspect a bad keyboard. And the network
card can be shorted. And line voltage is too low. And some
metal fragment is shorting the motherboard. And the power
switch is internally stuck. Its called 'wildly speculating'.
Click to expand...

The way *you* do it it is.
Yes the 'what it can be' solution means he must replace
everything until he found the one real problem or until the
stray short just fell out.
Click to expand...

Maybe you "must" but not rational people
Its called shotgunning.
Click to expand...

No, "shotgunning" is replacing things without any idea what might be wrong.
Sorta like whipping out a multimeter for every boot problem regardless of
checking anything else, except you're shooting with just one pellet.
Costs
more money. Takes more time. Sometimes only fixes the
symptom rather than the problem.
Click to expand...

Poppycock.

In the first place, your universal-and-nothing-else multimeter PSU probing
won't find a dead processor, shorted/dead PCI/AGP card, nor a whole host of
other problems, including a problematic fan speed sensor.

If your car mechanic used shotgunning, then we would call it
a scam.
Click to expand...

No, we'd call him incompetent. We'd be more likely to call it a scam if he
whipped out a multimeter and probed the distributor regardless of the
symptom and to the exclusion of everything else.
Get the meter. Identify the problem in two minutes.
Any other solution is simply trying to do things harder - not
smarter.
Click to expand...
The fan as a possible reason
Click to expand...

Yes, it is.
- wild speculation -
Click to expand...

No, it's based on knowing how motherboard fan speed sensing works and what
happens when there is no/low fan speed.
shotgunning.
Click to expand...

No more than you assuming every boot problem on the planet is caused by the
PSU.
 
David Maynard said:
The way *you* do it it is.


Maybe you "must" but not rational people


No, "shotgunning" is replacing things without any idea what might be
wrong. Sorta like whipping out a multimeter for every boot problem
regardless of checking anything else, except you're shooting with just one
pellet.


Poppycock.

In the first place, your universal-and-nothing-else multimeter PSU probing
won't find a dead processor, shorted/dead PCI/AGP card, nor a whole host
of other problems, including a problematic fan speed sensor.



No, we'd call him incompetent. We'd be more likely to call it a scam if he
whipped out a multimeter and probed the distributor regardless of the
symptom and to the exclusion of everything else.



Yes, it is.


No, it's based on knowing how motherboard fan speed sensing works and what
happens when there is no/low fan speed.


No more than you assuming every boot problem on the planet is caused by
the PSU.
Click to expand...
Thanks David, I was beginning to think I *HAD* to buy a multimeter! (or at
least dig out the one I have lying about here somewhere) and not just use my
years of acquired knowledge.
And you never know, one day Mr Tom may even learn to bottom post, like what
you are supposed to.

SteveH
 
SteveH said:
Thanks David, I was beginning to think I *HAD* to buy a multimeter! (or at
least dig out the one I have lying about here somewhere) and not just use my
years of acquired knowledge.
And you never know, one day Mr Tom may even learn to bottom post, like what
you are supposed to.

SteveH
Click to expand...

You're welcome, but don't get me wrong. I certainly use my handy dandy
multimeter to check PSU voltages, when it's appropriate. It just isn't the
only thing to look at and might not be the first either, depending on the
symptoms and circumstances. And it, for sure, isn't a cure all.

But I wouldn't be caught dead without one either. It's just too dern useful
a tool and any electronics hobbyist should have at least an el-cheapo.

On the other hand, of the "pc won't boot" problems I've run into most, by
faaaaaar, have not been PSU related.
 
On Fri, 11 Mar 2005 16:51:03 -0600, David Maynard <[email protected]>
wrote:

Over many years and thousands of service calls I found it overall a
time saver to meter or scope the voltages. Also looking at fuses
doesn't show a possible open thats non visable.
 
IDIDIT said:
Over many years and thousands of service calls I found it overall a
time saver to meter or scope the voltages. Also looking at fuses
doesn't show a possible open thats non visable.
Click to expand...

And why did you snip out from my message----

"I certainly use my handy dandy multimeter to check PSU voltages, when it's
appropriate ...
I wouldn't be caught dead without one either. It's just too dern useful a
tool and any electronics hobbyist should have at least an el-cheapo."

----
 
IDIDIT said:
I love it when self appointed GODS tell people what they are supposed
to do. IN WHAT COMMANDMENT DOES IT RESIDE-- THE SAME ONE THAT SAYS
EASY TO READ CAPS ARE NOT ALLOWED? TRY TO BE WELL!
Click to expand...

When you reply to someone put your message in the proper place with proper
attribution. There's not one word from me in what you left in here.

However, since you drug me into a topic I had intentionally said nothing
about, just because you're apparently uninformed of proper netiquette and
posting protocol doesn't make those who are "self appointed GODS." It
simply means they're informed.
 
IDIDIT said:
I love it when self appointed GODS tell people what they are supposed
to do. IN WHAT COMMANDMENT DOES IT RESIDE-- THE SAME ONE THAT SAYS
EASY TO READ CAPS ARE NOT ALLOWED? TRY TO BE WELL!
Click to expand...
I'm not by any means a 'self appointed god' I was simply quoting RFC 1855
which outlines the proper netiquette for posing on newsgroups. Perhaps you
should study it before you criticize. Here, I've made it easy for you:

- If you are sending a reply to a message or a posting be sure you
summarize the original at the top of the message, or include just enough
text of the original to give a context. This will make sure readers
understand when they start to read your response. Since NetNews, especially,
is proliferated by distributing the postings from one host to another, it is
possible to see a
response to a message before seeing the original. Giving context helps
everyone. But do not include the entire original!
http://www.faqs.org/rfcs/rfc1855.html

HTH
SteveH
 
RFC1885 permits top posting as long as one requirement is
met. It says:
... summarize the original at the top of the message, or include
just enough text of the original to give context.
Click to expand...

Furthermore RFC1885 requests not quoting the entire message
- which is what bottom posters do. The message begins by
providing context in conjunction with the previous message.
No where does that say to or even imply bottom posting. So we
review how IDIDIT posted:
Over many years and thousands of service calls I found it
overall a time saver to meter or scope the voltages. Also
looking at fuses doesn't show a possible open thats non visable.
Click to expand...

He provided context of the previous post (meter used to read
voltage) and provided a useful response - all in but two
sentences. He met the requirement of RFC1885 - which does not
require bottom posting. Summaries are not explicit quotes.
Then IDIDIT went beyond what RFC1885 requires. He quoted the
previous post at the bottom. IOW he put his footnotes,
references, and bibliography at the end of his writing. This
is beyond what RFC1885 requires. He organized a very readable
post as informed people do. Nanny netiquette intolerance
demands bottom posting.

RFC1885 only requires that this post summarize that previous
post. Same is taught in English composition class. One
starts writing by making obvious what topic or previous
message was - provide the context. English composition also
does not require bottom posting to "summarize the original".

In the meantime, returning again to the OP, David Maynard
posts:
On the other hand, of the "pc won't boot" problems I've run
into most, by faaaaaar, have not been PSU related.
Click to expand...

This is but another reason why using the meter is so
important to find and eliminate problems quickly. Power
supply is only one component of a power supply system. Any
part of that system could create the OPs 'power lost in one to
two seconds' problem. Meter could quickly identify which
power 'system' component is defective OR exonerate the power
supply system entirely. SteveH - what other method will
identify or exonerate so much so fast - in less than 2
minutes? Is it the power supply or the load? Again, the meter
reports so much so fast. The OP is encouraged to get the
meter, learn what is wrong, and only then fix or replace the
defective part.
 
In the meantime, returning again to the OP, David Maynard
posts:

This is but another reason why using the meter is so
important to find and eliminate problems quickly. Power
supply is only one component of a power supply system. Any
part of that system could create the OPs 'power lost in one to
two seconds' problem. Meter could quickly identify which
power 'system' component is defective OR exonerate the power
supply system entirely. SteveH - what other method will
identify or exonerate so much so fast - in less than 2
minutes?
Click to expand...

As has been pointed out to you many times in the past - experience. The
experience of having fixed loads of PC's, quickly and mostly without the aid
of a multimeter.
As I have pointed out already, the symptoms this board is exhibiting are
consistent with the CPU fan speed sensor not working or the fan not being
plugged into the correct header (amongst other things admittedly). Now,
would you check for this first or go prodding here, there and everywhere
with yer blessed multimeter?
I check the quick and obvious first, then if I have no joy, I resort to
getting out the meter etc.

SteveH
 
As experience has tried to teach Steve, much time would have
been saved by just looking at a meter. Others tell him his
methods take double the time or longer. But then intolerance
also means one cannot learn from experience. Within seconds,
one sees facts with a meter. The OPs problem is consistent
with a power supply that looses one voltage either due to
power supply system problem or elsewhere. This can happen to
all computers. Only some computers have or even use a CPU fan
speed sensor. So how did a computer that was working suddenly
disconnect its fan and then connect fan to a wrong connector?
Yes it is possible that the fan diconnected. So why does the
fan spin for one to two seconds if it is disconnected?
Another god appointed event?

The OP is encouraged to get that meter. Verify the
integrity of a power supply that, for reasons internal or
external, starts to power up and then shuts down. Get
facts. If numbers from the meter are not understood, others
with far more experience than Steve can then provide useful
information.
 
Only some computers have or even use a CPU fan
speed sensor. So how did a computer that was working suddenly
disconnect its fan and then connect fan to a wrong connector?
Yes it is possible that the fan diconnected. So why does the
fan spin for one to two seconds if it is disconnected?
Click to expand...

Well that just proves how little you know about motherboards then. I haven't
built a PC in at least the last 8 years (and I've built very many) hasn't
had fan speed sensing on the mobo. And in nearly all cases, speed sensing
that stops the board from starting if it can't detect the fan going round at
a sufficient speed for any reason (to protect the CPU).
And guess what, one of the symptoms of not being able to detect the fan
properly is the fans rotating for a second or two and then stopping
(experience tells me).
However, the last PC I fixed with these symptoms had a faulty PSU, which was
simply proved by swapping in a spare.

A Suggestion Mr Tom - lets give it up. We are not going to agree on this. I
just happen to fault find PC's the same way 100's (if not 1000's) of others
seem to, and most of the time it works for us. It's just not the way you
want to do it. What is wrong of you is to bring peoples intelligence or
ability into question (as you have done in the past) just because somthing
isn't done the way you would do it.

SteveH
 
w_tom wrote:

In the meantime, returning again to the OP, David Maynard
posts:



This is but another reason why using the meter is so
important to find and eliminate problems quickly. Power
supply is only one component of a power supply system.
Click to expand...

True, but it's the only thing you ever talk about putting a meter to.
Any
part of that system could create the OPs 'power lost in one to
two seconds' problem.
Click to expand...

It's "possible" in the philosophical sense like it's "possible" invisible
aliens are doing it. Invisible aliens are less likely than the 'motherboard
part of the PSU power system' but then the 'motherboard part of the PSU
power system' is less likely than, in this case, a BIOS safety shutdown
function.

And even if it were the cause it's unlikely you'll find out why "power is
good now but off 2 seconds later" with a multimeter that accurately shows
you "power is good now but off 2 seconds later."
Meter could quickly identify which
power 'system' component is defective
Click to expand...

Then why don't you ever tell anyone where to probe in that not-in-the-PSU
portion of the "power system" you harp on so much?
OR exonerate the power
supply system entirely. SteveH - what other method will
identify or exonerate so much so fast - in less than 2
minutes?
Click to expand...

One example: noticing that the fan isn't running thereby causing the system
to shutdown on fan failure. Grand total 5 seconds, if you have slow eyeballs.

You claim that probing the PSU rails will either "identify or exonerate"
but that isn't necessarily true either. Say the PSU is shutting down
because of an internal component over heating. Power is good, for a while,
and then, wham, it's gone. How does seeing the power rails look good, then
die, either identify OR exonerate? (How could it happen? excessive dirt
ingress or PSU fan failure, to name two).

If he has a cocked heatsink letting the CPU overheat you could probe the
"power system" all day long and not learn anything about why "power is good
now but off 2 seconds later."

I'm not saying either of those is likely either but, rather, that you're
grossly over stating the necessity and 'omniscient' utility of a multimeter.
Is it the power supply or the load?
Click to expand...

And what about neither? This may come as a surprise but PSU and motherboard
failure are not the only causes of boot problems.
Again, the meter
reports so much so fast.
Click to expand...

That isn't the issue. The issue is your claim it's the one and only way
under all circumstances and symptoms, as well as omniscient and infallible.
The OP is encouraged to get the
meter,
Click to expand...

I already recommended that anyone dabbling in electronics should have a
multimeter but I'd also recommend that one not just automatically crack the
case and begin PSU probing every time a boot problem crops up.
learn what is wrong,
Click to expand...

Which, in the vast majority of cases, will take something other than a
multimeter.
 
Step one: confirm the power supply system. What is step
two? Unknown until we have information from step one using
the meter. Numerous strange failures are created by a power
supply problem. Do we chase those strange failures with
shotguning? Instead power supply integrity is so easily
confirmed in minutes. Only then do we move on to step two.

Why post step two? Maybe 50 possible step twos exist.
Data from step one means only a few possible step twos - none
involving aliens. No sense posting so many possible step twos
until facts from step one have been learned. But then you
knew this.

Look at the Original post:
I press the power button and the speakers make a beep the
fans spin for 1-2 seconds then they stop spinning
Click to expand...

Is this a power supply, a shorted soundcard on one voltage,
a stuck power switch, a non-spinning fan, or a long list of
other problems? Do we swap out everything? The meter tells
us in but a minute which possibles to verify. Maybe the power
supply system works fine. Maybe one voltage is stuck
shorted? Maybe one voltage is marginally low? Maybe the fan
causes a Power On signal to be lost. Or maybe the power
supply sees excessive loading on one essential voltage and
cuts off the system. Or maybe the power switch gets stuck for
a few seconds. Will you then replace everything? Or learn
from meter readings where to look next?

Again, in the OPs case, how the 3.3, 5, 12, Power Good, and
Power On signals work in the first two seconds provides major
information on where to look next. Too many possibilities to
post without first learning from step one.

Could it be a power problem. There is nothing that can be
eliminated faster. Once the power supply system is verified -
the foundation of every computer - then the remaining reasons
for failure are vastly reduced. Problem made substantially
simpler to solve.

Fastest way to isolate the problem? Once the power supply
system is confirmed, then the number of possible reasons for
failure are significantly reduced - in less than two minutes -
and without all that laborious swapping parts.
 
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