No beeps when starting a computer with a black screen

One of the members at our senior center has a computer that boots up only with a black screen and there aren't any beeps at all: LED lights are on. The owner has a system repair disc and noise can be heard from it spinning but the screen stays black. I recommended to the owner to change the CMOS battery but he won't do it because he measured the voltage and it passed. So I recommended he bring the computer to a computer repair shop, he hasn't done it yet but that's his decision.

But out of my own curiosity shouldn't there be some beeps when a computer starts up with a problem, in this case the black screen?

See these links on POST beep codes and troubleshooting:

What is POST?
Computer POST and beep codes
POST troubleshooting steps

Ask the end user to perform the following step using the keyboard:

Click: win + control + shift + b (all four keys simultaneously)

Ask for the response.

These will occur if Windows is responsive:

Did the display refresh?
Did the computer make a sound?

zbook said:

Ask the end user to perform the following step using the keyboard:

Click: win + control + shift + b (all four keys simultaneously)

Ask for the response.

These will occur if Windows is responsive:

Did the display refresh?
Did the computer make a sound?

Never knew about this shortcut, thanks!