Won't come on or boot up

[Beccabob2008]

My hp all in one intel pentium gold Black screen 3 long beeps and 4 short beeps with white light won't boot up or come on

[Bill_To]

Greetings @Beccabob2008 

My pleasure.

Your AIO PC has a power delivery problem.

You can review a 3:4 startup error code at this HP Site.

The MB is getting power from the external power brick but this does not mean the power brick is not causing the startup problem.

There is a power problem happening with either:

- The power supply

- One of the memory modules or the CPU

- The M.2 WIFI card 

- The MB since other components are integrated into the MB

You might want to have a local PC Tech take a look if your PC is not in warranty.

Regards