HP Probook 450 wont turn on

[Malone_Nick]

This did it for me! Literally was losing my mind taking everything apart to see why it wouldn't turn on. Sometimes it's the overlooked obvious.

[Ockenio]

My HP Probook 450 G3 won't turn on. I have tried a hard reset but it still won't turn on. when I plug in the DC adapter ( without the battery) white light came in the power button only once. It doesn't blink repeatedly 

[zick2500]

Ockenio,

Did you find a fix for yours yet? We also have a Probook 450 G3 that is doing the same thing.

The AC port LED, power button light, and cap locks light all come on for a second when either inserting the battery or connecting just the AC charger. But the laptop will not power on. Have already tried the hard reset.

[Ockenio]

Hi Zick2500;

No, I haven't found a fix for it. I assume it may have something to deal with the motherboard. I have already written it off as damage and I in the process of purchasing a replacement Laptop

[jkingham]

I had a similar problem with an HP ProBook 450 G2 - if you plugged in the adaptor, the power light, CapsLock light etc would flash once , but nothing else ever happened.  None of the reset procedures worked.  Somehow I wondered whether it might be a corrupted BIOS, but the BIOS battery is not easily accessible.  In the end I dismantled the laptop completely and removed the motherboard, then removed the CR2032 Lithium battery underneath the motherboard which backs up the BIOS, for about 30 seconds.  On replacing the battery and reassembling the laptop, everything worked as normal.  It took about an hour, but I can understand why this is not a procedure which can be recommended to an end user.  But if you have an expensive laptop which is otherwise dead, it might be worth finding someone else who can do the job for you.

[Ockenio]

Yes it as worked but as soon as i finish screwing up my laptop it stop working again. I suspect i have a faulty hardware.

[Ockenio]

I finally found the source of my problem. The problem I having is my power switch is not working ( The circuit). I will need to change that circuit soon. For now i have to be using a flat-head screw driver to touch the pins to start my machine..