What are basic diagnostic tests on a Windows laptop that won

[Calia]

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.

 

[Calia]

On Mon, 26 May 2014 03:28:54 +0000, Calia wrote:

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

Actually, now that I have said that, my second timer run
shows the fan continually running.

So, to clarify, the only indications of anything working
are the fan runs continually, and a few LEDs light, as
stated prior.

Curiously, the hard disk drive LED light on the left
side does not seem to be lighting up at any point.

 

[Geoff]

Calia <calia@its.invalid> wrote in
news:llucdm$jre$1@news.albasani.net:

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.

Bad RAM will stop boot too.

 

[Calia]

On Mon, 26 May 2014 00:50:51 -0300, pjp wrote:

I take it it's not under warranty?
The warranty died long ago.

> Even with the hard disk toast, I'd expect to see the display come alive.
Nothing shows up on the display.
Here is a picture with the power on and the fan running:
http://oi59.tinypic.com/2h3a3oz.jpg

> Has the power brick given up?
I don't know. I will try to get test leads into those tiny holes.
It appears to be charging the battery and the battery appears to
work, so, I've tested all three cases:
a) With just the battery
b) With the AC power and the battery in
c) With the AC power and the battery out

http://oi61.tinypic.com/2lj6bdv.jpg

 

[Calia]

On Sun, 25 May 2014 22:40:42 -0500, Jon Elson wrote:

> Does it have a door you can remove to get to the memory card?

It's a little tricky removing those memory cards.
They seem to have a fancy "clasp" on the sides, but, I will
keep trying until I get them out:
http://oi61.tinypic.com/hsmiqc.jpg

> You might also pull the hard drive and re-insert.
I am taking your advice and have removed the hard
drive, and will re-insert soon:
http://oi60.tinypic.com/5wbfa8.jpg

 

[Calia]

On Mon, 26 May 2014 04:18:13 +0000, Calia wrote:

> It's a little tricky removing those memory cards.

I removed the two memory cards, and swapped them, and put
them back, and powered up, but to no avail.

http://oi57.tinypic.com/73h4rm.jpg

 

[Calia]

On Sun, 25 May 2014 21:13:55 -0700, Jeff Liebermann wrote:
> (Complete and accurate model numbers are always helpful).

My mistake. I apologize.

Inside the battery bay is the model & product number:
Model G72 B54NR
Product XR826UA#ABA

> Usually, it's bad BGA chip soldering.
I had to look up Ball Grid Array, which, when I found what it
was, looked far beyond my capabilities.

Is there anything on the screen?
Nothing.

not, take a flashlight and shine it around the upper left of the
screen, where the BIOS boot messages appear

Tried that. Nothing that I can see.

> HP Blinkenlighten codes:

Thanks Jeff.
I had no idea those keys were blinking a code!
I followed the procedure at the suggested location:
http://h10010.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=c01732674&product=1132551#N213

Basically, I removed the power & battery & discharged the computer
by holding the power button down for 30 seconds and then hooked
just the AC power but not the battery.

1. The AC adaptor light at the right side goes white.
2. The capslock & numlock light stays white (i.e., no blinking).
3. The F12 is a steady orange.
4. I press the POWER switch.
5. I hear the fan but not the HDD nor do I hear any beeping.
6. The AC adaptor light on the side of the PC stays white.
7. The capslock & numlock keys blink once for 1 1/2 seconds,
and then they go off for 4 1/2 seconds.
8. I can discern no other pattern than that 1.5:4.5 seconds!

The really bad news is that a single blink in the table reads:
"CPU not functional"

Is that as horrible as it sounds?

 

[Calia]

On Mon, 26 May 2014 05:06:15 +0000, Calia wrote:

The really bad news is that a single blink in the table reads:
"CPU not functional"

I found this video which at least shows me how to disassemble
the HP G72 B54NR to get at the CPU to see if it can be debugged:
http://www.youtube.com/watch?v=VXrXMSOShA0

 

[Calia]

On Sun, 25 May 2014 21:13:55 -0700, Jeff Liebermann wrote:

> Usually, it's bad BGA chip soldering.

I will likely try overheating the motherboard, to solve
this problem, as per this video on the HP G72:
http://www.youtube.com/watch?v=IgH98o3cu0A

 

[pjp]

In article <llucmg$jrf$1@news.albasani.net>, calia@its.invalid says...

On Mon, 26 May 2014 03:28:54 +0000, Calia wrote:

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

Actually, now that I have said that, my second timer run
shows the fan continually running.

So, to clarify, the only indications of anything working
are the fan runs continually, and a few LEDs light, as
stated prior.

Curiously, the hard disk drive LED light on the left
side does not seem to be lighting up at any point.

Ugh!!! I take it it's not under warranty? Even with the hard disk toast
I'd expect to see the display come alive. Has the power brick given up?
That's about only test I can suggest, e.g. is it providing 12 volts or
whatever. Try to find another rated more or less same and try it
instead.

Other than that if it's not under warranty and you can't find some
"specialty shop" deals with laptops almost exclusively you likely have
some parts is about it, e.g. hard disk can likely be used in some
enclosure as an external drive etc. Fact of the matter is cost of time
to repair likely comes close to cost of replacing. Sorry for your loss.

 

[Paul]

Calia wrote:

On Mon, 26 May 2014 05:29:51 +0000, Calia wrote:

I will likely try overheating the motherboard

If the overheating of the motherboard doesn't work, is it
feasible to remove the motherboard and somehow, "reflow"
the solder joints?

For example, in this video, a guy removes & replaces
a chip with some sort of brass torch tool:
http://www.youtube.com/watch?v=zHpeLYb-puw

Is the IC replacement as easy as that video makes it seem?
(Seems to me the chances of getting all the pins lined
up and nothing shorted elsewhere has got to be near zero.)

You use a hot air rework station for BGA replacement.

http://product-image.tradeindia.com/00401612/b/1/Manual-Hot-Air-BGA-Rework-Station-G500.jpg

On good quality PCB material, a BGA site can be repaired
up to three times, without damage to the PCB.
Computer motherboards are not high quality,
so your mileage may vary.

The hot air rework, applies heat from the top
of the PCB. It also applies heat from the bottom.
This is to reduce stress on the PCB. On the top side,
the area to be heated, is controlled by fitting
a metal "hood" to the nozzle. There are different
sized hoods for different sized chips. (We had
at least 20 different ones for our machine at work.)

On the top side, a "vacuum wand" can be used to lift
the molten-hot chip off its PCB site. That's when it is
hot enough. The small knob on top of the tool in
the picture above, could be related to chip release.

When you put down a new chip, the soldering process
is "self aligning". When the new chip is heated, to make
the solder balls melt, the surface tension of the solder
helps "attract" each contact, to its mate on the PCB.
So even if the chip is rotated 1 degree from ideal
position, it will "snap" into position when the
solder melts. This reduces soldering defects to around
1 bad connection in 100,000 solder balls.

When a repair is finished, a 2.5D Xray machine can be
used to verify the quality of the solder joints.
Pictures are taken, using Xray energy, at an angle off
the vertical axis. And any balls with a "popcorn" problem,
can be seen in the picture taken with the Xray energy.
I've never seen one of these in person, but our factory
had one. Every large chip was verified with one of these
(as part of closed loop process feedback). Eventually,
once all the kinks are worked out of the manufacturing
process, this might not be as necessary.

http://www.koreaittimes.com/story/28756/escatec-invests-%E2%82%AC150000-25d-x-ray-inspection-system-further-improve-quality-control

A company in town used to do this repair here, but
they charge $1000 per chip. They have this high charge,
because their staff are mostly idle. And the company
has likely long since closed up and moved. In Taiwan,
where staff do this for a solid eight hours a day, the
cost of repair is a lot lower.

Depending on the ball count, pitch, and so on,
there may also be "underfill" materials squirted
underneath the chip. This forms a solid which helps
control stress when the product is at its normal
operating temperature. I know nothing about how
you deal with underfill, when such a chip needs
a repair. Underfill would be a popular solution
for stand-alone GPU chips. (I don't even know
what materials to use, so this is just an illustration.)

http://www.namics.co.jp/e/product/chipcoat03.html

*******

Home computer repair people, they use the "oven
method" to repair GPUs. Which is about as dumb
and dangerous as it sounds. While the repair
may seem to work at first, the track record
of such repairs is not perfect. Temperature
profile is completely uncontrolled - plastics
may melt on items which were not intended for
this sort of treatment. Proper repair with a hot
air rework station is better, because the temperature
profile is controlled during the entire operation. You
can use the chip manufacturer recommended profile,
when doing a repair.

Paul

 

[Calia]

On Mon, 26 May 2014 05:29:51 +0000, Calia wrote:

> I will likely try overheating the motherboard

If the overheating of the motherboard doesn't work, is it
feasible to remove the motherboard and somehow, "reflow"
the solder joints?

For example, in this video, a guy removes & replaces
a chip with some sort of brass torch tool:
http://www.youtube.com/watch?v=zHpeLYb-puw

Is the IC replacement as easy as that video makes it seem?
(Seems to me the chances of getting all the pins lined
up and nothing shorted elsewhere has got to be near zero.)

 

[Paul]

Calia wrote:

On Mon, 26 May 2014 01:29:41 -0400, Paul wrote:

Try to match the table info, to your machine. Applies to
UEFI BIOS machines.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01443366&cc=us&dlc=en&lc=en

I get a single blink, which translates to:
LEDs blink 1 time, CPU, CPU not functional

It seems the CPU disconnects from the motherboard due to solder
cracks, at least if I understand Jeff correctly.

Not necessarily true. It could be the VCore regulator
near the CPU socket which is not functioning. It could
be a loss of power feeding into the VCore regulator (like
a problem with the circuit distributing power from battery
to elsewhere inside the computer).

CPU/Processor chips are very reliable.

On laptops with a separate GPU chip, some of those have
problems with cracked solder balls. But for the
CPU socket, it could be using a thruhole socket
with land grid array springs to make contact with
the CPU. And that doesn't have nearly the same issues
as a fine pitch BGA might.

Also, when you see LEDs blink, they may not be
blinking due to the "test procedure". They could
instead blink because of the way a power failure
is happening inside the unit. For the entries in the
table with multiple blinks, seeing the LED blink
multiple times would be a reasonably reliable
indication of a problem. But when you see one blink,
is that a "CPU test failure", or is it "the power
regulator just turned off". We don't know. Some
test results will not be that accurate and specific.
And it would be a mistake to jump to a conclusion just
yet.

I would retest with battery pack IN versus
battery pack OUT, and see if the timing of the
blink changes at all. If if was a true CPU
test failure, the timing should not change at all.
If the blink duration seems quite different,
between those two test cases, it could be an
internal power distribution issue.

Paul

 

[Calia]

On Mon, 26 May 2014 01:29:41 -0400, Paul wrote:

Try to match the table info, to your machine. Applies to
UEFI BIOS machines.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01443366&cc=us&dlc=en&lc=en

I get a single blink, which translates to:
LEDs blink 1 time, CPU, CPU not functional

It seems the CPU disconnects from the motherboard due to solder
cracks, at least if I understand Jeff correctly.

 

[Paul]

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.

Black screen with blinking error code LEDs are described here.

Try to match the table info, to your machine. Applies to
UEFI BIOS machines.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01443366&cc=us&dlc=en&lc=en

And this is my proof that a G72 may be using a UEFI BIOS.

http://h10025.www1.hp.com/ewfrf/wc/softwareDownloadIndex?softwareitem=ob-88666-1&lc=en&cc=hr&product=4293043&os=4062

Paul

 

[Paul]

Calia wrote:

On Mon, 26 May 2014 04:18:13 +0000, Calia wrote:

It's a little tricky removing those memory cards.

I removed the two memory cards, and swapped them, and put
them back, and powered up, but to no avail.

http://oi57.tinypic.com/73h4rm.jpg

You test the memory SODIMMs, one at a time.

Do not insert both.

Try only one of them.

If still a problem, remove that one and try the other.
It is unlikely for them to both fail at the
same time (although that has happened to me).

Paul

 

[Jon Elson]

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?

Does it have a door you can remove to get to the memory card? if so,
remove the memory card, clean the contacts (gently) if they
appear dirty, and re-insert. You might blow dirt out of the
connector before putting the memory card back in.

Otherwise, some computers have various connectors between various
components, and some of these can work loose with handling. There's
always a connector for the LCD screen, but these are likely very
hard for a non-expert to get into. You might also pull the hard
drive and re-insert. Sometimes that will fix a problem, although
you'd usually get a failure message when it can't read the hard
drive.

Jon

 

[Jeff Liebermann]

On Mon, 26 May 2014 03:28:54 +0000 (UTC), Calia <calia@its.invalid>
wrote:

>I have a Windows 7 HP G72 laptop which suddenly stopped working.

Jumping to a premature conclusion, I would guess(tm), that you have
the same problem as all these people:
<https://www.google.com/#q=hp+g72+laptop+will+not+turn+on>
Usually, it's bad BGA chip soldering.

>Do you have an idea how to do basic troubleshooting?

Unplug the charger. Remove the battery. Go away for about 10
minutes. Put the battery back in and do not plug in the charger. If
the battery is totally dead (i.e. shorted from sitting at zero charge
for too long), it might not turn on. If you suspect that you have a
shorted battery, and can't find a suitable replacement, remove the
battery, insert the charger, and see if it will power on with just the
charger.

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

That might be an HP G72-227WM. Is that correct? (Complete and
accurate model numbers are always helpful).

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.

Ummm... It should go at full blast for about 2 seconds, and then spin
slowly. 40 seconds implies that some timer on the MB is not working
normally.

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

OK, the power switch is working. Is there anything on the screen? If
not, take a flashlight and shine it around the upper left of the
screen, where the BIOS boot messages appear, or in the center of the
screen, where the Windoze logo normally appears. If you see
something, then the backlighting is blown. The G72-227WM has an LED
backlight, so there's no inverter to replace. The problem will be to
determine if the lack of backlighting is caused by a problem on the
motherboard, LCD panel, cable, or connector.

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

White means it has power. Orange means it's charging. No light means
that it's charged. Flashing means your battery is so low as to not be
able to power the laptop.

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

HP Blinkenlighten codes:
<http://h10010.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=c01732674&product=1132551#N213>
This should give you some things to check.

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

That's meant for users, not techs.

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

Yes, I can. Try asking in the HP support forums:
<http://h30434.www3.hp.com/t5/Notebook-Hardware/bd-p/Hardware>
Hint: You'll need to provide a better description of the flashing
lights and boot errors.

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

In my never humble opinion, the last few years of HP and Compaq laptop
are not worth fixing. I hesitate to fix them because they don't stay
fixed. I often see them back in a few months, usually with a
different problem. Details and horror stories on request.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Calia]

On Mon, 26 May 2014 01:50:09 -0400, Paul wrote:

I would retest with battery pack IN versus
battery pack OUT, and see if the timing of the
blink changes at all.

The timing of the single blink remains whether I use the
battery or the AC power supply without the battery.

I am googling how to reflow the motherboard and it looks
like I have three major options (none of which are really
all that good).

1. Cover all fan ports & run the PC hot for 20 minutes.
2. Disassemble & reheat specific chips (e.g., cpu).
3. Disassemble & bake motherboard in the kitchen oven.

None seem particularly safe.

 

[Calia]

On Mon, 26 May 2014 06:53:56 +0000, Calia wrote:

> 3. Disassemble & bake motherboard in the kitchen oven.

Here is the procedure I may need to follow:
http://www.computerrepairtips.net/how-to-reflow-a-laptop-motherboard/