Elitebook 840 does not power on at all

[meistersyncer]

I have had an Elitebook 840 for 3+ years. This morning, it suddenly would not turn on.

Symptoms:

- after pressing the power button, the keyboard's LED lights turn on for a 1/2 second before everything goes black again. This 1/2 second flash repeatedly happens every 5 seconds or so, as if the computer is repeatedly trying to boot up, but is unable to

- I have tried booting up with various power combinations (battery-only, A/C-only, both), with the same cyclical 1/2 second flashing after pressing the power button

- when the A/C power cord is connected, the little indicator light on the front edge of the laptop is not on anymore

Any help would be welcome!

Thank you.

[CF4]

Hi

Can you match with any of the combinations here?

https://support.hp.com/us-en/document/bph07107

1st Please try a Hard Reset
This is valid for most notebooks, and some desktops.
Press and Hold the PWR off button for 4 seconds to force a PWR off.
Unplug from the wall.
IF you see a battery compartment door, then your computer has a removable battery.

IF NOT then you do not have a removable battery.

Remove any removable battery.
Press and hold the power button for 15 seconds to complete the reset.

(Re-insert any battery you removed).

[meistersyncer]

Thanks for the suggestions about observing any beeps or blinks.

However, there are no beeps (sounds).

There are also no "blinks", but just a repeated turning on for a 1/2 second of all the computer lights (like a regular bootup). All computer lights flash for 1/2 second, every few 5 seconds or so.

I tried both the hard reset, taking the battery out and holding the power, and these did not help either...

[CF4]

Hi

Elite Books are well Elite and not something I want to suggest any further repairs on.

Sorry.

[SRK90]

Hi Even I have same problem with my laptop (HP Elitebook 840 g1), can you suggest me if you got solution or suggestion .

[CDK9]

Hello there....I as well am facing the same challenge...I have an HP 840G1 touch laptop. When I try to power on it doesn't respond instead in keep blinking every after about 5 secs on the power on button, capslock, and the power and charge symbols along the edge of the laptop...it is quite frustrating...any help?