Charging LED blinking orange (500ms freq)

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HP EliteBook 840 G6

Troubleshooting and repair guides for the HP EliteBook 840 G6 laptop computer, a 10/10 iFixit rated laptop released in 2019.

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Chris @crisb76675

İtibar: 13

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Gönderildi: 9 Mar 2024

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Charging LED blinking orange (500ms freq)

My 840 G6 doesn't turn on anymore, regardless if I plug in the original charger or a 100W USB-C PSU.

The only sign of life is a blinking orange LED beneath the charging port.

I tested original charger with multimeter, so that is fine. Also I checked the USB-C PSU. When I plugin a volt/ampere meter to the USB-C charger I can see the PD communication from laptop to PSU is fine: it get's up to 20V and pulls 0.4A.

I also tried to detach battery and CMOS battery, press power button for 15-30 sec then only attach power supply. Unfortunately that didn't help.

Does one have an idea what that blinking orange charger LED means? Only thing I can find online is according battery things. But that LED also blinks if if detached the battery and only provide power supply.

Are there good points to test voltage on the motherboard? Does the battery voltage pins need to have ~11V if PSU is attached?

Update - 2024-03-10:

For my feelings it's pulling to much current: 420mA with not battery attached. Feels like there is somewhere a short.

I did different measurements, but don't know how to narrow it down from here. Can someone guide me on measurements?

Update - 2024-03-14

Seems like the thunderbolt controller (or some peripheral of that) causes an issue. I tested with my fingers which chip is getting really really hot and it's that JHL7340.

Can one say if it must be that chip causing issues if it's getting hot, or if that might be related to some of its peripheral? I'm wondering if it's really shorted, as PD exchange with USB-C PSU is still working (but maybe it's not that chip doing PD exchange?!)

Update - 2024-04-29

I did a lot of reading and repair video viewing (thanks Sorin) now and decided to order a replacement chip on aliexpress as well as a cheap hot air station on amazon. After some trials on an old broken PC motherboard, I replaced that BGA chip in a fearlessly mood with the new one, with the result of "no short anymore".

Unfortunately that doesn't seem to be the only thing... Measurements on the main power rail look like the second mosfet is also shorted (0 Ohms resistance). So first mosfet gets 20V input, on the output it's gone...

So now, as I have the tools, I ordered that one on aliexpress too and will try to replace it. Will keep you updated, just in case someone stumbles over that topic here.

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mike @aactech İtibar: 28,5b 9 13 64 · Answer 1 · 2024-03-09T19:25:12-07:00

Could be a corrupted BIOS.

Here are some of the symptoms you may experience after trying to restarting the HP laptop:

Windows does not start and the caps lock or num lock keys blink, or the computer beeps 2 times
Power light or charging light continues to blink
A BIOS APPLICATION ERROR 501 is displayed
The computer stops at a black or blank screen when turned on
The computer turns on and you might hear the internal fan, but the display is blank and Windows does not start

Note: Different models may use different keystrokes.

You can try:

Turn off the computer and be sure that the AC adapter is connected to power.
Press and hold the Windows + b keys, and then simultaneously press the power button.
After 2 to 3 seconds, continue to press and hold the Windows + b keys, but release the power button. You might hear a series of beeps.
- If the HP BIOS Update screen is not displayed, repeat the previous steps but press the Windows + v keys. If the screen is still not displayed, your computer might not support the feature or there is a hard drive issue.

There is also the USB drive method. Download the latest BIOS update for your HP laptop on another computer and make a bootable USB drive

This HP site gives more details. Key strokes may be different for different models.

Read the direction several time and make sure you follow them exactly. Timing can be very important.

Here is another video discussing the HP corrupt BIOS repair.

Good luck. Let us know how it goes.

Thanks Mike for your detailed answer. Unfortunately, it didn't help. I tried with different key combos, timings and USB slots.

I don't think it's coming to a stage where this mechanism could kick in. Beside the blinking charging LED there is no other indicator for power. No power light, no fan... — Chris

HP EliteBook 840 G6

Charging LED blinking orange (500ms freq)

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