Question:  How can I diagnose/attempt to locate the defect that has
paralyzed my notebook PC, and possible fix it? Could it be a defective
heat sensor?
For your answer, you may asssume reasonable PC skills (software and
hardware, including some dexterity with a screwdriver and a
volt-meter) on my part, but I don't think I could totally re-built the
notebook from scratch.

I look forward to your input!
Background:  the PC in question is a 2.4 Ghz P4 desktop replacement
computer made in Taiwan, sold here about 2-3 years ago as a SAGER
P5620.  I have a fully updated antivirus always "on", ditto for
firewall, it's running WIN XP professional SR2.

The problem is as follows:  Two days ago, the machine died in the
middle of work, w/o any other previous sign of trouble.  The on/off
button works fine, but the computer does not even begin to spin the
hard disk, although the indicator LED will come on  for a second or
two.  Fans etc. are working, and the ON/OFF LED is ON.  O.K., I
thought, maybe the hard disk crashed.  However, and this is the
problem, the machine does not give error beeps as expected when no
bootable disk is found, AND (this is the kicker) is did start o.k.
twice in about 10-12 attempts to boot it up, it did boot all the way
up to XP, I could even access explorer for a few seconds, and then the
machine died within 1-2 min.after start.
This time it flashed an error screen (blue with white text) but that
was for about 1 second before the screen went dark again.  Also, I was
unable to get into the BIOS setup during a few attempts when it didn't
boot at all.

This sounds very much like a defective hard drive to me. Everything
you have described does in fact indicate so. The curious thing is your
inability to get into the BIOS, but definitely make sure that you are
powering all the way off, and then back on rather than just attempting
a reset.

To recover your data, and to test my belief that it is the hard drive,
there is a simple test you could easily try at home.

By using some other form of bootable media, such as a floppy or CD Rom
or USB device, it will bypass your hard drive, and, depending on if
this media has recovery software, will allow you to access the hard
drive if it hasn't crashed too bad.  But just the fact that you're
able to boot to some other device would indicate hard drive issues
rather than anything else.

My personal favorites are Spinrite, On Track and the BartPE bootable
CD.  The first two will cost you, but Barts can be created for free
with a little trouble of reading the website to learn how to create
it. It will allow you to access you hard drive and copy the data to a
network drive, providing you are on a network.

Some more free options include creating a bootable floppy off another
machine, although this is very limiting, or using some of the free
bootable 'nix' CD such as Knoppix and FreeSBIE.  These CD's boot in to
the 'nix' environment but allow hard drive access and network support.
 Another option would be to simply insert your recovery CD or a
bootable XP CD (or any bootable CD) and just see if it'll boot. 
Obviously if your hard drive is bad, booting to the recovery CD won't
fix it, but you'll know it the drive and not the computer.

Good luck and keep up posted.

PJ

hmm, I had a very similar experience with Toshiba laptop, at first I
thought it?s the hard drive as well but I try to boot up with XP cd,
few times it works and died before it get to repair screen. (So you
might want to start with CD to make sure if it is hard drive or not.)
In my case it was memory and one of my memories was damage (I know
doesn?t make sense but exact same symptoms as your case) so try to
boot it up without the ram and see if works.

Good luck

I would have to agree with bobpour.  Although my experience with
laptops is limited, I am thoroughly experienced in both software
diagnostics and pc hardware and troubleshooting.  I've had similar
problems with improperly seated or damaged RAM dimms/simms.  If the
computer isn't beeping, it isn't posting.  Your RAM and CPU should be
checked first, along with your video card.  With onboard video in a
laptop, the first thing I would try is swapping out your RAM.  See if
you can find someone with similar RAM/take it to a PC store and see if
they'll let you install a stick in store with the promise of buying it
if that is the problem.  If the hard drive were dead, it should still
post (it would on a PC) and give you an error message after the system
test finishes.  Also, because the computer crashes so hard when you do
manage to boot, I don't believe it is the hard drive.  You should sit
at the BSOD if it were the hard drive (IMHO), where as a RAM or CPU
problem would likely force the machine to auto reboot/shutdown. 
Another way to test the HD is to buy a laptop to IDE converter (5-15
dollars, worth the investment, comes with a bracket too).  This would
let you stick your laptop HD in a PC and see if you can browse/scan
it.  I would bet you can.  Let us know if you get a chance to swap out
the RAM and test (and if you have expanded your RAM, trying booting
with one stick at a time and see if that helps, possibly isolate a bad
stick).  Good luck.

Hi,

Thanks to all of you for your comments, your input is much
appreciated.  I am still struggling with the problem, and I followed
up on the comments about the memory being loose or fried etc.  I
checked that, took out and re-seated the CPU, put everything back
together and the machine worked fine for about one hour, when the
problem began again. However, I can now certainly rule out the HD as
the trouble-maker, since my PC did work w/o a hitch during that time. 
I also noticed that the fans did not come on as long and often as I
remember from before, since the machine was now mostly (but not
always! quiet, which it was not before, i.e. the fans connected to the
heatsink did not come one as often and long as "normal", when the
machine sounded more like a mini-blowdryer.  I am now wondering
whether it's the heat sensor that's causing the trouble.  Anybody has
suggestions/experiences how to check/fix that in the labtop situation?

Thanks

reallymadscientist

PS.  braininhouston:  Good point with the labtop to IDE adapter, I
will get one ASAP no matter what the cause of my problem is, you're
right that it is worth the peace of mind to have one.

i have a very similar problem. I too have been having a problem with
my laptop booting up. first time i was able to boot up as normal, then
it froze. so i restarted it and then when it got to the login page, it
shut down on its own. out of the few times that i could get it going,
i was able to get into windows, the BIOS and able to use the win xp cd
to boot up - each time it just shut the computer down. Now i can get
it to boot up. i can turn it on, and the CD drive does it thing, but
thats it. green light on, no problems, but it wont even boot up now. -
any ideas?????

cheers,

Jamie

Guys, you have failing hardware. If I were you I would let an
experienced PC technician handle it. Especially when you are saying
the machine is a p4 2.4 ghz machine. That machine isn't new enough to
still be under warranty? If not it's still new enough to be taken to
an EXPERIENCED hardware technician that can properly diagnose, order,
and replace the defective parts.