startup issue

[Big1975]

all in one 20-c434 startup it gives error unsupported adapter then in a few seconds it will power down

[sandytechy20]

@Big1975

Welcome to the HP support community.

I understand that you are getting an unsupported adapter error, I am glad to assist you.

Update the Bios, chipset, and drivers using HP Support Assistant.

Download and run the HP Support Assistant from this Link: Click here

• HPSA will automatically search for all the latest drivers for your Notebook
• Click My devices in the top menu, and then click Updates in the My PC or My notebook pane.
• 
• Click Check for updates and messages to scan for new updates.
• 
• Review the list of updates. Updates with a yellow information icon are recommended. Updates with a blue information icon are optional.
• Click the update name for a description, version number, and file size.
• Select the box next to any updates you want to install, and then click Download and install.

Also, ensure Windows is up to date.

• Select the Start  button, and then go to Settings  > Update & security  > Windows Update , and select Check for updates. If Windows Update says your device is up to date, you have all the updates that are currently available

Let me know how it goes.

To thank me for my efforts to help you, please mark my post as an accepted solution so that it benefits several others.

Cheers.

[Johnharper241]

Check the power supply and battery. If your HP laptop won't turn on even when plugged in, start by checking the power supply.
Diagnose screen issues.
Remove all devices from your laptop.
Use a rescue disc. .
Boot in safe mode.
Check hardware.

Regards,
John