Calia wrote:
Those of you with experience troubleshooting a dead
laptop, can you provide advice?

I have a Windows 7 HP G72 laptop which suddenly stopped working.
Do you have an idea how to do basic troubleshooting?

What happens when I try to reboot is that nothing shows
up on the 17-inch screen whatsoever.

The only indicators are the fan and a half dozen LEDs.

The fan is most notable.
When I press the power switch, the fan goes on for what
I timed at 40 seconds. Then the fan goes off.

The white LED to the immediate left of the topside power
switch glows white when the computer is turned on.

The orange and white LED next to the power input on the
right side of the pc also glows either orange or white.

The white capslock key LED blinks white synchronously with
the NumLock key. The F12/WiFi function key glows orange.

The tiny LED on the DVD tray button does not light, nor
will the DVD tray open unless I insert a paperclip.

I found this "maintenance guide" but it doesn't seem to
list these conditions:
http://h10032.www1.hp.com/ctg/Manual/c02623152.pdf

Those of you with experience troubleshooting a dead
laptop, can you provide advice?

Mainly I just want to know if I can pinpoint the failure
and then I can see whether it's worth trying to fix.


You have received a lot of useful information and suggestions, so what I
am about to say may be for naught: I have two G72 laptops. One I
bought new and experienced much the same type of problem as you are
after the warranty ran out. Being that I am one who cannot accept a
device is not repairable, I dug into trouble shooting and repairing my
laptop. At first I opened it up and inspected the connections because
the problem was intermittent. I would disassemble the computer,
reassemble it, and it would work for a time. Then it would fail again.
Without going into great detail of all the steps, the solution to
fixing this computer was to re-solder the connections at the power
switch board. There appears to be an opto isolator on a daughter board
where the switch is mounted. It takes a steady hand and a low wattage
iron, but this computer has not failed in a couple of years since I
touched up the connections. I think I fixed it.

After having fixed the above computer, I purchased another G72 computer
on Ebay where the seller was encountering the same failure as mine. I
bought it for little, and thought I would use it for parts if my
computer ever failed. When I received it, it DID NOT include an AC
adapter. I plugged in my adapter to the computer and everything
worked!! That has been over a year now.

So what can one learn from the above? First off there appears to be
some experiencing such failures that are attributed to the power switch
board. There are such posts on the web. Second, if the adapter
delivers less than the proper level of voltage to the computer, it too
will fail in a similar manner. Measuring the voltage with a volt meter
is not going to work unless you load it down sufficiently. If it were
my computer, I would borrow a power adapter that you know works on that
model computer. If it does not solve the problem, suspect the power
switch board.

There are no guarantees as to what will solve your problem, and the fan
running seems to contradict my experience, but a lot is happening when
you start a computer. Any of them failing will negate the boot process.
Good luck.