Why won't my HP Elitebook 8450p turn on?

Question

I suppose before I get into the details, I should provide a tl;dr. My HP Elitebook 8450p absolutely will not power on, under any circumstance.

A more detailed description of my problem:

I'm currently in a PC repair class, which mostly consists of my professor giving us a desktop that doesn't necessarily work, and making sure it works, installing a specific OS, and getting it in running order. Currently, I'm working on an HP Elitebook 8540p laptop as a side project; this is not going to be graded, it's just to learn more. He gave me the laptop, told me it doesn't turn on, and left me to my own devices. I looked it over, and sure enough, it doesn't turn on at all.

Connecting a battery or charger gives me one blinking LED, the one that represents charging. It starts blue, but immediately turns orange for a moment, turns off, then repeats. HP's given manual shows that it's not an error code.

I've confirmed that the problem is not the RAM or the CPU, as I've changed both out. I checked the charging cable for power with a multimeter, and it was giving what it needed. Going on with the multimeter, I checked different parts of the mobo. Some areas, such as the RAM slots and the WiFi adapter showed low voltage, but other areas, like the heatsink fan connector didn't give any power at all, along with all external ports, and I'm really at a loss for what the problem could be.

My teacher suggested it could be a shorted port, but I'm not sure how I could test it, or even fix it. The multimeter showed no power in them, and they're soldered directly to the mobo; they can't be changed anyways, at least within the scope of the class. My worry is that

I'm absolutely stuck on this laptop, and I was wondering if I could get some advice or ideas to try out. I think I should mention one more time, this is not a graded assignment, this is more or less for fun and to get experience with laptops; helping me actually can't change my grades. Sorry for the long post. Thanks

Answer 1

Interesting question, but I suspect this may be more suitable for an electronics site - it would appear to be an issue with the motherboard.

That said, have a look at http://h30434.www3.hp.com/t5/Notebook-Hardware/EliteBook-8540p-Not-Powering-On/td-p/2858537 which looks like it might solve your problem -

Please read that thread, but the solution put forward there is:

1. unplug your battery and charger from your laptop.

2.open the 3 screws of keyboard from backside(downside) of your laptop.

3.open the keboard clips from upper side carefully and put it out.

4.now you will see the three or four strips near to your touchpad, disconnect these strips from motherboard.

5.Plug just your battery in and push the power on button.

Answer 2

I wanted to share something in case it helps others.

My Elitebook 840 ran out of charge and shutdown, when connecting to power I had a flashing white LED battery indicator and it wouldn't power up or recharge.

I checked everywhere for a solution but ended up discovering a thin brass pin in the connector had been bent and wasn't inserting into the AC port properly, I carefully straightened it to the centre of the connector, inserted back into the laptop and it worked perfectly immediately.

Sounds simple but the pin is hard to see and it took Quite a while to work this out. Seems to me a very weak part of the pin assembly.

Hope this helps someone.

Answer 3

I've had a few HP Laptops, and seen a few similar problems. I just fixed one that was similar but not exactly the same, so I thought I would post it here in case it helps others with various similar symptoms.

My laptop started booting, then turned off. I was sometimes able to see something on the display. I had tried the unplugging batteries, holding down the power button etc to reset BIOS to factory defaults, but it did not work. Odly, what worked for me was to press escape to go into BIOS, choose defaults, then save and exit, shutdown, then turn on again. Curiously, it started booting and Windows said "Installing Updates", so I wonder if it was a corrupted BIOS or confused Windows Updates, or a combination of the two.

Answer 4

This worked for all the laptops that didn't boot up for me (never tried with my desktop tho). I'm a tech savvy guy so I am pretty surprised myself that this works (might for you since you still have the light indicator)

1. Remove battery

2. Remove power adapter

3. Hold the start button for 1 minute (more just to be sure)

4. Connect the power adapter but not the battery

5. Try to boot and if it works you can then put the battery back in

Also I am not so sure that its the connector. I previously had a Toshiba satellite laptop with a faulty connector and there were no light indicator popping up. It might also be your HDD but if it was, the computer would post but Windows will not load. Worst case scenario: it's the part in your motherboard that contains the BIOS that is done or simply the motherboard is done.