hp envy x360 - 13-ag0502sa booting into black screen after shut down during BIOS update

[Watchman34]

HP Envy x360 - 13-ag0502sa - Windows 10.   This notebook belongs to my grandson who shut it down during a BIOS update. He mistakenly thought this was a virus attack and panicked ... I thought these youngsters were more IT aware!! When the notebook is switched on the CAPS lock key displays 3 long and two short flashes but screen remains black. Does anyone know of a way it can be restored? I have tried the Windows +  B key combination when starting up but this fails (both methods have been tried). Your suggestions would be most welcome, especially if I can prove to him us oldies still have active brains!

[Watchman34 · Accepted solution]

Hi everyone, I have worked out a solution to this post but you need to be a techie to handle it. If you are willing to give it a try, here is how it's done but you should be aware that you take full responsibility if anything goes wrong.

It involves dismantling the notepad to gain access to the Li-ion battery. I recommend you download the service manual (http://h10032.www1.hp.com/ctg/Manual/c06027358) before going ahead. The tools you need for this are mentioned in the manual at section 4 'Tools required' and are easily obtained from Amazon or eBay. It is also important that you wear an anti-stat wrist strap to prevent static electricity from causing damage once you gain access to the sensitive components beneath the back cover.

First, uplug the power input, and make sure the notepad is switched off. Place the notepad, lid side down, on a non-slip mat such as that sold by Amazon (Rose Evans® Multipurpose Non-Slip Mat). This will protect the lid from scratches and prevent the notepad from sliding about. Gently remove the rubber cushion strips to gain access to the 6 Philips screws holding the base of the notepad in place. Now remove the screws from top and bottom and place them safely aside. Next, remove two Torx screws along the slightly angled edge of the base, then safely set aside the screws. Using a plastic pry tool, start at the hinge side and start gently and progressively prising the back away from the notepad.  You now have access to the components inside the casing. All you need to do now is carefully disconnect the battery lead from the main board and set the notepad aside for about an hour. It may not need to be this long but I decided to err on the side of safety. You can now return to re-assembling the notepad, making sure you reconnect the battery lead before fitting the cover into place. After replacing all the screws, the rubber cushion strips should fit back easily but may have stretched a little. If so, simply snip off any surplus and press firmly down. Having completed this, switch the notepad on and it should take you through the process of restoring the BIOS back to its previous configuration.

As I stated earlier, you attempt this at your own risk but with care and the proper tools you should have the same success that I experienced.