hp m8200n wont boot

[MoundainDrew___]

my hp m8200n won't start and I can't figure out why.

when I hit the power button it makes a beeping noise that lasts about 5 seconds and all the fans wurr to life.  but nothing will display. it's hard to say whether the hard drives stay on, but there is an audible jerk of the arm when I hit the power button

upgrades

• 2x8 ram
• ATi Radeon GPU

[A4Apollo]

Hi! @MoundainDrew_, Welcome to HP forums.

I understand you are unable to boot into your PC you see a black screen.

Don't worry I will try to help you out.

How many times does the PC beep when you power it on?

Are you able to boot into BIOS?

Please provide the operating system you are running on your PC to assist you better.

As you mentioned that you have upgraded memory and graphics card on your PC.

Try removing the memory from your PC and check if you are able to boot into your PC.

If you unable to boot into your PC, try placing one memory at a time in different memory slot and check if it helps.

If you are able to boot into BIOS try the steps mentioned below.

reset the BIOS to make sure the BIOS settings are correct:
Turn on the computer and press F10 repeatedly to open the BIOS setup screen.
Press the F5 key to reset the default BIOS settings. Use the arrow keys to select Yes or OK and press Enter.
Press the F10 key to save settings and exit. Use the arrow keys to select Yes or OK and press Enter.
Turn off the computer.
Remove the power cord.
Press and hold the power button for five seconds.
Reconnect the power cord and turn on the computer.
If the startup problem is gone, you are done.
If the startup problem still exists, continue to the next section.

Also, refer this document to know more about beep codes on a desktop PC.

Let me know if this helps!

Have a wonderful day ahead! 🙂