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Old December 27th 07, 08:42 PM posted to alt.comp.hardware
twomt
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Posts: 7
Default Computer won't start

Paul wrote:
twomt wrote:
Joel wrote:
twomt wrote:

Hello,

I fear I have a hardware problem somewhere, can someone give me some
hints on how to locate the root cause?

The computer is getting power as the fan is blowing normal and the
keyboard lights (caps-lock, num-lock and scroll-lock) blink once
when I press the power button.

Then it all stops, well... the fan continue to blows but nothing
else happens. This is before the bios screens come up when you
initially start your computer.

The monitor turns itself off saying it does not receive a signal,
the keyboard is not responding to anything (normally, num-lock would
show the light on/off) and my optical mouse is not showing the red
lights it normally does.

I've let it run for a while, but the state does not change.... it's
broken :s

Any ideas what might be causing?

Me? these are what I usually do.

1. I read and learn thing *before* thing starts happening to my
system as
many and I doing at the moment. What I am trying to do is encouraging
others to take a opportunity for future problem.

2. I would try to see *if* it causes by hardware or software.

- Hardware - I would go to CMOS setting screen, and often most
problems
solve itself just by entering the CMOS setting. Or usually the
CMOS will
detect something changed and recogize and fix itself.

Then check either Power-supply, memory, video, audio cards etc.
make sure
them have good connection.

- Software, then sometime just boot to .. I forget what it's
called .. ohh
"Safe Made" can sold some software/hardware related issue
itself. Or on
safe mode Windows may have to load some specific program, then
update the
working Windows to normal boot. Yes, sometime it's so weird but
works
sometime

Or booting using util like util called "Winternal" and I don't know
exactly what it does, but my systems with booting issue were
solved by
just boot with "Winternal". But I ain't recognize to jump
straight to
Winternal without taking a chance to learn what's going on.

Thanks,
twomt


1. I am not getting this statement...

2. CMOS, as I wrote the PC locks up / stops booting before this point.
I haven't been able to get into the CMOS. Because it already happens
at this point, I am suspecting a hardware or bios issue. If it was
software, I would imagine that it would stop only at a later point.

I've already unplugged the cards and stuck them back in, no change.
As most of the stuff is on-board, I can't do a lot with it anyway.

The other option to reset the CMOS is probably the best way to go
forward for now. And perhaps to find a spare-parts PC that I can use
to see if I can locate the root cause.

But thanks for your response anyway.


Some simple things you can try, are disconnecting I/O devices from the
machine. For example, disconnect the USB devices outside the case
first. If some I/O device has died or is malfunctioning, they may
be confusing the BIOS.

Open the machine, disconnect the data cables from the hard drive and
CDROM drive. Using a piece of paper, make notes of where the cables
go, so you can put them back exactly as you found them.

Other checklist items:

1) In this case, we know your BIOS is executing. The flashing of the
keyboard lights is a positive sign. It means the processor is
executing (so the processor does not need to be reseated), the
BIOS code was executed (so the BIOS isn't completely fried -
the main block of BIOS code has probably passed the checksum
test). I'm not sure about RAM. Maybe the RAM test would still be
an item yet to be completed by the BIOS.

2) Turn off the computer and unplug it. To work inside, you want
all power removed (not for risk of shock or anything - it is
to protect your hardware). The reason for unplugging, is to
make sure +5VSB is disabled, and that there is no power present
in the RAM slots. At least one poster with a broken computer here,
had a power supply with a broken switch, and the power supply was
on, even though the power switch was set to off. Unplugging ensures
there aren't any incidents like that.

Remove and reseat the RAM.

3) If you have multiple sticks of RAM, try the machine with only
one of the sticks plugged in. That may not be enough memory,
for an OS to boot properly, so may not represent a usable
system configuration. But the purpose of inserting only one
stick of RAM, is to see if you can get the BIOS screen to appear.
If a stick of memory goes bad, it may prevent POST. In some
cases, the computer beeps if the memory is bad. But it
is also possible the BIOS just hangs.

4) Clearing the CMOS is a good test. But you'll also have to restore
any custom settings in the BIOS. And I have to admit, on my oldest
machine, when the CMOS battery died, I was at a loss to remember
what some of the settings did. It did take me an hour or so of
experimenting, until I got the hang of it, and the machine was
able to boot with a new CMOS battery.

While power supply failures on computers are a frequent source of
problems (and not completely eliminated in your case), the fact
that the keyboard lights blinked gives me hope that the power
is good enough to allow the POST process to get further than it
currently is. For example, a computer that restarts, just as the
Windows desktop appears, could be having a power problem. But in
your case, the power consumption should be reasonably stable during
some of the BIOS tests, and the BIOS doesn't appear to be getting
past things like NVRAM or RAM test, or enumerating hard drives
and optical drives.

Paul


Thanks for all the advice, this goes for those posting after this
message as well.

Here's what I have done so far:

I took my TV-card out - No change
All external devices are unplugged (only monitor, keyboard and power are
connected) - No change
Took the CMOS battery out, left it for 10 minutes (power cable
unplugged), then restarted - No change

Then I took my video card out, although I can't see anything the
computer suddenly started bleeping (when starting it) and at least my
keyboard seems to be responding (num-lock light goes on/off when I press
num-lock).

Does that mean my video card is busted? I don't have a spare on, so I
can't really test it. The only spare one I have doesn't fit in the slots
on my mainboard.

Thanks,
twomt.