HP laptop doesn't power up

Dear Fellow Users,

I am kindly asking for your help. I have an HP DV7T-6C00 laptop which doesn't power up at all. I have read various forum threads and they did not solve my problem that's why I'm opening a new one.

It started about two weeks ago, when it didn't want to wake up from sleeping, only after removing battery and plugging the charger in. It seemed odd, so I did backup from everything. Ever since then it does not power up at all.

When I plug the charger in (without battery), the charger indicator light is on with a steady white. If battery is in the result the same. If I have the battery disconnected from the laptop for a while, the light is orange (meaning that it's charging) and it becomes white (meaning that it's fully charged).

I tried various solutions to solve the problem, including the following:
- disconnecting every external device
- power up with only battery,
- power up without battery but with charger,
- hard reset (for 15 sec, 30 sec, 2 mins holding the power button),
- removing one RAM module, another and both,
- removing hard drive,
- removing optical drive,
- checking ZIF connectors,
- holding the power button for 15 sec.

No fan sound, no beep sounds, no emergency LEDs (Caps Lock and Num Lock), nothing except for the charger indicator light. Also, I can feel the power button is working.

I happen to have a multimeter and with that I was able to exclude the charger as a possible cause since its voltage is within norm.

I have two guesses: the motherboard and the CPU. Unfortunately I have no replacing capabilities to check them without being sure which is the cause.

The challenge is open for everyone, thank you for your answers in advance.

Some laptops won't power up if the battery is not working, but I doubt that's the issue in your case. So far I've only seen that on Medion laptops, and I own a HP myself - pretty sure it should work without a battery.

That is indeed a rather intriguing issue. Seems like you're stuck in a difficult position.
I would normally suspect some kind of hardware fault such as motherboard failure. It could be something much simpler such as faulty power jack, which I doubt since the little light comes on.

Here are my suggestions:

1. Try a different charger, was yours ever getting very hot?

2. Remove the battery AND the CMOS battery and do a hard reset, then plug the charger in (without CMOS or the laptop's battery) THIS WILL ERASE YOUR BIOS SETTINGS. Doing so on my laptop would cause it to power up without having to press the power button.

petvanhun said:

Viper13 said:

Some laptops won't power up if the battery is not working, but I doubt that's the issue in your case. So far I've only seen that on Medion laptops, and I own a HP myself - pretty sure it should work without a battery.

That is indeed a rather intriguing issue. Seems like you're stuck in a difficult position.
I would normally suspect some kind of hardware fault such as motherboard failure. It could be something much simpler such as faulty power jack, which I doubt since the little light comes on.

Here are my suggestions:

1. Try a different charger, was yours ever getting very hot?

2. Remove the battery AND the CMOS battery and do a hard reset, then plug the charger in (without CMOS or the laptop's battery) THIS WILL ERASE YOUR BIOS SETTINGS. Doing so on my laptop would cause it to power up without having to press the power button.

Thanks for replying.

I have already tried a different charger, just forgot to mention it. I can't remember if it was getting hot.

Pretty good idea, I don't know why it hadn't thought of it earlier. I will try it right now, when finished will share the results.

I have the same result - nothing. However, I noticed that when I plug the charger in the light suddenly fades for a second and starts to glow again. Could this be important? I was also given a tip that the cause may be the heatsink. I'm gonna check that as well.

I'm afraid I don't have any more suggestions for you to try, but it sounds more and more like a hardware failure (motherboard).
I will continue to think about your issue and get back to you if I'll have any more suggestions.

Now that I think about it though... it might be a corrupted BIOS. I can't remember whether that would cause it to show a black screen or not turn on at all though. Hmmm, it should at least turn on (fan, screen, leds) even with a corrupted BIOS.

If it was only the monitor and not the mobo then you'd hear and see some LED activity from the mobo or HD.

You can get it determined for sure by going to a store like Best Buy to have the Geek Squad give you a free mobo test. This is what I sometimes do to save time. If you call ahead they will tell you if they can do it then.

Well, well...I thought it won't be solved, but life is funny (and it still isn't).

I've tried accidentally with another (a third one which has almost the same voltage but almost half Amper) charger - it turned on! It did even restart with a Ctrl+Alt+Del combo. However, after I turned it off (with the power button, because there were no HDD in it), it did not want to power up again.
Somehow, I managed to find a way with hard resetting, changing adapter and taking the battery out and putting back it, to power it up. I played it three times.
Now, I am a bit confused and awaiting for your wisdom and advice.

Thanks!

Google your laptop make/model + replacement charger to replace the charger with one of the correct voltage and amperage for your laptop.

gregrocker said:

Google your laptop make/model + replacement charger to replace the charger with one of the correct voltage and amperage for your laptop.

But it does not restart with the another charger just powers up once. How would it solve my problem?

I'm only pointing to the need to have the correctly spec'd charger. If your charger is not working then you'd want to replace it and not just use a random charger.

Here in the states we have a chain Best Buy where I often take a PC which I need the mobo or PSU tested for free, usually calling ahead to ask when is best to bring it by. Maybe you have them or similar there. They would plug in their universal charger to see if it is stable and then you'd know for sure. They can also test the mobo and HD.

You can test your HD and RAM from Troubleshooting Steps for Windows 7 using the boot disks provided.
But you'll need to have a stable power supply first.