HP Compaq 6604au Notebook PC - No Display and No POST

This does not sound like a firmware issue, nor any other kind of software problem. In all probability, your display is out, since it did blank rather suddenly. This could be as a result of any number of things, ranging from a burnt out back light to a burnt out GPU on the motherboard.

One very quick and dirty thing you might try is plugging in an external monitor, if the machine has a VGA socket, or other video out. If you get a video signal to the external monitor, then you know that the problem is in the display panel somewhere. If not, then it's on the board and it's time to consider a new machine.

Hi DrMoose,

Thanks for your comments... I have tried plugging in another monitor to the VGA socket of this laptop. And I tried the key combination to switch to the secondary display.. But nothing happened.

As mentioned, when powered on all the LEDs on the top of keyboard are on and it stays at a status where my DVD drive (already a dead one) makes a sound as if it is trying to seek some disc inside it. The LED of DVD drive blinks.. and on each blink.. the LED light of my HDD also blinks..

Can the above actions happen if the BIOS is not functional?? And if bios is okay, then why am I not getting the alternate display? Above why there are not any beeps heard???

As soon as it went blank, I had rebooted the system -- it had turned on and was on the resuming window (from hibernate)... as this screen did not pass after a long time.. I powered it off again and tried to turn on... It was since then.. these issues started. If motherboard was faulty or burnt, would it have turned on again...at least once??

I have removed my HDD and tried various options like pressing ESC key and F2 key while powering on the lap but to no use..

Okay, what has happened is that your video has gone out. Meaning that either your discrete GPU or integrated graphics (depending upon which you have) have burnt out, or the associated circuit pathways have. As I said in my previous remarks, if your video chips and circuits were still functional, you would have had a video signal at the VGA plug, if only the POST and BIOS screens.

What this means is that everything else is still working, but there is no video signal going out to either your display panel or to your VGA plug. This is why you still have LEDs blinking and such. And so unfortunately, your only repair option is to replace the motherboard. The problem being that your machine is already several years old, this is not the only problem you've mentioned with it, and it's probably not worth the cost of the repairs.

I hate to have to tell you this, but your best, most cost-effective course of action is almost certainly going to be to replace this machine. Though you can probably salvage the old HDD by putting it into an external enclosure.

Hi DrMoose,

Thanks for the details... being curious what could have caused to my display all of a sudden... Can it get damaged if I install any plugins? Asked this because it happened very soon after I executed an exe file of TVU file which I got downloaded from a reliable source (a website of a local daily which has live streaming of their news )

Raj, I am very familiar with the DV6600 series from HP, having purchased one for my ex-wife some years ago, and having worked on several others for friends. The bottom line is that this is a consumer-grade laptop, and it's several years old. You probably got it in what? 2006? 2007? Most consumer-grade laptops don't live more than two or three years, so the machine has already out-lived it's expected service life.

As to what specifically caused the failure? Without a rather expensive analysis, it's almost impossible to say. Though I rather doubt it was anything you downloaded. There seems to be very little malware out there which can actually attack hardware, though it's not completely unheard of.

Raj,

I suggest you click on the following link: http://www.nvidiasettlement.com/

Probably the problem and solution(?) would be there...

Hi No

Thanks. .but my model (6604au) is not listed there...

Just to make sure that its not the fluorescent tubes, take a torch and look at the screen with the torch to see if you can see anything.

I recently had my laptop sceen go defective in this way.....it was also difficult to switch to the external screen......don't know why, but seeing that the screen was working, but that the backlight was gone helped....sounds crazy but true.....

I hope this helps....

Read back Andy. He has no video output at either the display panel or the VGA plug. This indicates that the on-board video is gone. If it was the panel, there would still be a signal at the plug.

Beolieve me, that may not be true.

When switching displays without being able to read the main screen, its really easy to make errors, thats what I was doing.

That was the reason I asked him to check with a torch/flashlight, costs nothing!!!

I understand your point sir, but, on the first restart after the problem manifested, he didn't even see the POST screen. If the POST screen was visible, then it would be likely that it was a software issue. However, this particular failure indicates to me a hardware issue.

If the screen is damaged in the way I am trying to identify fully, thats exactly what he will see from the Post screen - NOTHING. He will not see anything of any screen (though some screens work for a short time from cold, but no guarantee! Some flah occasionally, again nmo guarantee)

I am still hoping he will do exactly what I have asked, it costs nothing to check and may help him in finding the REAL problems......until he does it, none of us will ever know.....

Here is the point. He hooked up an external monitor, but when he fired the machine up, still did not see anything displayed. So, unless his CCFL backlight and VGA out circuit burnt out at pretty much the same time, this is a motherboard issue.

Though I do agree with you that holding a very bright flashlight against the screen to see if he can light it up is a quick, painless, no cost check that is worth doing.

It may depend on the laptop, but my Toshiba does not send data to the external screen until a certain combination of keys are pressed (in the correct sequence), in this case completely "BIND".

It took me several "goes" to get it right (when my laptop screen broke in this manner) and several more goes to get it to stay.....

Which is why I am suggesting that low cost test, just let the PC boot and then look at the original screen using a torch/flashlight!!!!

Its so cheap to do......and may help!!!

I (sadly) cannot follow your reasoning 100%. You may be right, but you may also not be right!!! The same for me, my test costs simply nothing and can be done by anyone.....

You could well be right, but until the test is made, that will not be a "100% fact" as really needed....

Surely the OP can take the time to have a look and report back?

You make an interesting point, as I cannot say for certain that the HP/Compaq does send a signal to the VGA plug at all times. Though I confess that your Toshiba is the first I've heard of that doesn't. If I did in fact have this machine in front of me for troubleshooting, the first thing I would do would be to download all the pertinent manuals from HP, so as to find out such details. And, I would in all probability do a flashlight test on the panel. As you've pointed out, it is a very simple and quick test.

Although most of the laptops I have had were Toshiba, I have used many others as well, none displayed an external signal if not selected to do so......I don't pretend to have a perfect memory, but I recall none that always sent to both the external and the internal screens.....

Some remembered it for the next boot, most don't......I cannot say if this HP does or does not, but booting and then looking at the screen with a torch (in low light conditions) will let the OP know one way or the other.......

Simple and very effective....... K.I.S.S. and make up?

So, we have had exactly opposite experiences regarding VGA plugs. Go figure. I do agree with you however, that the torch test is a sensible thing to do in this case, whichever of us is right.

I forgot to add that to get the display where you choose which is the screen to display and which is also the secondary screen on a Toshiba, you press both the "Fn" and the "F5" Keys together.

Then you use either the cursor arrow keys or the mouse, to select the screen system from about 6(?) alternatives......

The boot screen will NOT ever be displayed on the second external screen, if you use the BIOS password for example, this always has to be keyed in "blind"......

I hope this helps in some manner the OP further....

It is rather a thermal damage and soon you need to replace the motherboard. Hopefully I'm wrong.