My HP 22 All-in-one doesn't start up, it shows nothing on the display and emits a beep code.

[king_diagnostic]

my pc doesn't start up at all, shows nothing on the display when the power button is pressed. it emits a beep code of 3 long beeps and 4 short beeps.

[Grzwacz]

HI @king_diagnostic,

A 3:4 BIOS error code indicates a hardware problem.

Troubleshooting steps are as follows:

You may need HP Factory service if in warranty or local PC tech service to isolate the failing component.

You could try self diagnosis. AIO PCs are difficult to work with. Plus you may need to buy components to find the bad part.

Regards

[king_diagnostic]

Yea I found that too, but how would I isolate these different components in an All-in-one?

[king_diagnostic]

bc the display shows nothing at all nor does the input devices operate correctly. 

[Grzwacz]

Hi @king_diagnostic,

It is impossible to isolate the bad component in a forum. A lucky guess might fix your problem. Or you could foolishly spend a lot of money on replacement parts with no return on your investment.

AIO PCs are similar to Notebook/Laptops. Just about everything is on the motherboard (MB). So if any integrated MB component fails you usually have to replace the MB.

You will need known, good replacement parts to find the bad component. It is easier to have a local PC tech find the bad part.

Components to check are the: power supply, RAM, CPU, or the MB. It is usually the MB if the power supply, CPU, and RAM are okay. The remaining connected components would be storage devices such as a HDD/SSD or an optical drive. Your product uses integrated Intel UHD graphics.

I can't find any teardown instructions for your PC. Most AIP PCs require removing the rear bezel by removing screws to access the internals.

Troubleshooting requires known, good replacement parts. This is why I recommended you have a local PC tech take a look. 

Regards