"unsupported adapter installed"

[DC82]

We have an HP All-in-One 24-dp0158qe with the original power adapter which will no longer power up correctly,     It goes immediately to the loud beeps (3 long, 4 short) which someone accurately described as like an Amber alert.    After 5 iterations of that, we get a black screen showing "unsupported adapter installed".      I've read all the other posts about disconnecting the power and removing the battery, etc.    We tried that and let it sit for hours, but that did not solve the problem.   We replaced the battery on the motherboard to see if that would help, but it did not.    We tried removing everything from the motherboard that we could disconnect (wireless card, 2nd hard drive, ...) and that had no effect.   We even borrowed a more powerful power adapter from a different HP All-in-One , but that didn't help either.      And, as always seems to be the case, this machine is no longer covered by a warranty.

We did find that if we hit ESC when the black screen comes up, that we can run all the diagnostic tests.    Those tests all run clean with no errors.   We can also hit ESC and choose to go into the boot menu.   When we do that, and then simply exit the boot menu with no changes, Windows boots up normally and everything seems to be working fine.     

Does anybody have any additional ideas on how to get past the alarms and the error message?

[Max3Aj]

Hi @DC82, Welcome to HP Support Community. 

Thank you for posting your query, I will be glad to help you. 

The issue you're facing—loud beeps (3 long, 4 short) followed by the "Unsupported Adapter Installed" message—suggests that the system is detecting an issue with the power adapter or motherboard's power circuitry. However, since you can boot into Windows by going through the boot menu, it's likely a false positive detection rather than a hardware failure.

Possible Solutions to Try:

Check Power Adapter Compatibility

• The error suggests the system is rejecting the power adapter as incompatible, even though you're using the original adapter.
• HP AIO PCs are very specific about their power adapter wattage and ID pin.
• Try another genuine HP adapter of the exact same model and wattage (even if a different HP AIO adapter didn't work, it might not be the right one).
• Check the barrel connector pin for damage or debris.

Perform a Full Power Reset

Since the issue might be caused by a stored power state:

1. Disconnect everything (power adapter, peripherals, etc.).
2. Hold the power button for 30-60 seconds to drain residual charge.
3. Plug in the original HP adapter only and power on.

Update BIOS & Drivers

Since you can access Windows:

1. Update the BIOS using HP Support Assistant or manually from the HP website:
   • HP Software & Driver Downloads
2. Update all drivers, especially chipset and power management.
3. If the issue persists, reset BIOS settings to default in the BIOS menu.

Disable Power Adapter Warning (If Possible)

Some HP laptops allow disabling the "Unsupported Adapter" warning in the BIOS settings.

• Boot into BIOS (ESC → F10) and look for an option like "Adapter Warnings" or "Power Adapter Detection".

Windows Power Plan Reset

Try resetting the power plan in Windows:

1. Open Command Prompt as Administrator.
2. Run the command: powercfg -restoredefaultschemes
3. Restart and check if the error persists.

I hope this helps. 

Take care and have a good day. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping! 

Max3Aj

HP Support