3 long beeps, 4 short beeps repeats 5x, error : unsupported adapter installed

[Machspeed]

I have a 27 inch pavilion all one model 27-a030.

It starts, then 5 times in a row it makes 3long beeps then 4 short beeps, next an error comes up: unsupported adapter installed, then it shuts off.

I tried reseating the USB keyboard dongle, reseating the power cord, moved to different outlets, I replaced the power adapter and the cmos battery, reseated the dimms. Tried also booting with hdd and disc reader unplugged. None of these steps has resolved the issue. Thanks for your help in getting my computer working again.

[Grzwacz · Accepted solution]

Greetings,

Welcome to the forum.

I am not a HP employee.

You have a  hardware problem.

A 3:4 BIOS error cadence can reviewed at this site (Link).

Scroll down to the 3:4 error code for details.

You replaced the power adapter, could be one bad stick of RAM or a bad memory socket. Interesting you are getting an unsupported adapter error. Disconnect all peripherals. Then see what happens when you start the PC.

You may need to have HP or a local tech find the bad component.

BTW, nice troubleshooting.

Not much else you can do. Most components are integrated on the MB.

Regards