Black screen after failed bios update due to bios corruption

[deflector]

Hi everyone,

A friend of mine broke the pin of his ac adapter which get stuck in the power port of his laptop and gave it to me for repair. I dismounted the back of the laptop, removed the pin from the port, added thermal paste on the cpu, cleaned the fan, and bought him a new genuine ac adapter.

Few weeks later, his laptop shutted down while working (he couldn't tell me if it closed properly or shutted down immediatly). At reboot,  he was prompted to do a bios update due to bios having been corrupted, which he did.

The update seemed to run fine, but after that , Windows refused systematically to boot and bsoded  with "critical process died" (right after the HP loading logo).

Having access to the uefi bios and diagnostic interfaces I did the following :

* run every diagnostics with no errors

* tried to boot Windows in safe mode -> bsod

* tried to start various recovery tools from uefi menu -> bsod

* booted with success to a linux live cd, and checked the hdd

At this point, I tried to update the bios again , the process seemed to run fine again, and now,

the laptop screen remains blank at startup. I have already tried the following with no success :

* Pressed ESC at startup

* Pressed F8 (low video resolution)

* Power resetting (holding the power button for 20sec)

* Boot to bios recovery (power button for 3 seconds while windows key + B pressed) with and without a usb recovery key

* CMOS clear (power button for 3 seconds while windows key + V pressed) :doing this make the led on the f6 key blinks every 1sec.

* All of the above with battery removed

* All of the above with battery, hdd, ssd, wlan disconnected

* All of the above with the ram stick swapped to the other slot.

* All of the above with a monitor plugged to the hdmi port (with pressing on  secondary display key  [F4])

The laptop do not emit  beeps nor blink patterns.

I didn't find the cmos battery on the motherboard to remove it so I guess that's the main battery's job.

I think I bricked the motherboard , but I'm not really sure, Did someone had resolved similar issue ?

Maybe I can flash the bios chip directly ? or physically reset the cmos (but I can't find it on the board) ?

Also I wonder how the bios bin would have been corrupted. I checked the mobo and it has no trace of damage.

It is me when I first dismounted the laptop ? Or could it be the new ac adapter that is disfunctional ?

Thanks.

[Echo_Lake]

@deflector

Thank you for posting on HP Support Community.

Don't worry as I'll be glad to help, I understand that your HP notebook is not working correctly. 

I appreciate your efforts to try and resolve the issue. The last thing I can suggest performing BIOS rollback will recover the computer from the error state. 

• Firstly, remove the hard drive from the computer.
• Once the hard drive is removed, turn on the computer without the hard drive- While booting as the computer doesn’t detect a hard drive, it’ll automatically roll back to the previous bios.
• Put the HDD back in and turn it ON. It might give an error about the improper shutdown. Just click continue and it should boot to windows.

Hope this helps! Keep me posted for further assistance.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.

[deflector]

• HI

First, I want to thank you for the reply.

As I said in the first post, I already tried to boot the laptop without the hard drive.

I tried also to boot the laptop without the SSD for I didn't know on which drive the OS was installed.

But since you hinted me to do this,I gave it another try.

I tried to simple boot, CMOS reset, and  boot to bios recovery with HDD unplugged with no success.

It gaves the same result : black screen, power and F6 led ligthen up.

Thanks again to you for trying to help me.

Cheers

[Echo_Lake]

@deflector

Thank you for posting back.

We are in your corner, Its sounds like hardware related issue with the computer and in order to fix this issue,  your computer needs to be serviced.  As we have limited support boundaries in the support community as of now. 

I would request you to reach out to our Support and our Support Engineers should be able to check the available service options in order to diagnose the computer physically.  HP Support can be reached by clicking on the following link:  www.hp.com/contacthp/​​​​​​​
 

Please feel free to contact us here anytime you need any further assistance. Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.