HP EliteBook will not boot

[phs_1337]

Hi,

My HP EliteBook 840 G3 won’t turn on. Here's what I've observed:

• The laptop is plugged into the charger, and the power LED stays solid amber (charging).

• When I press the power button, nothing happens — no screen, no fan, no noise.

• I performed a hard reset (30 sec power button hold) with and without battery — no success.

• When the charger is unplugged and I press the power button, I get this blink sequence:

1. The power light turns on, but the battery LED stays off
2. Then the battery LED blinks amber 9 times

3. Then both light go off

3. Then the battery LED alternates amber and white 4 times (white longer than amber)
4. Then battery LED go off

From HP documentation, I could see this kind of pattern can help diagnose the issue

Any advice?

Thanks in advance!

[phs_1337 · Accepted solution]

A clear CMOS without the battery connected (after a battery change) fixed the issue.

If I were to be again in the same situation I would first try the clear CMOS alone just in case.