DEll Inspiron 5721 four beeps black screen

Hi,

Welcome to our community. Were there any hardware or software changes made to the computer post which the issue occurred?

As per the diagnostic indicator, 4 beeps indicates memory failure. Reseat the RAM and try booting the computer.

Let us know the results.

last week

I already tried the RAM thing and it still beeps.

the keyboard was changed

Thank you for confirming Daniela. Do you hear the beep sound intermittently? Do you see the Dell logo once you power on the computer? If yes run the diagnostics and post the results. You can click here to find the video that has steps to complete the diagnostics.

Also, private message the following,

1. Service tag
2. Registered owner’s name of the system
3. Email address

To send a private message, click on my name and select ‘Send private message’.

The laptop gives tree sets of four beeps and then stops, it doesn't give the dell logo or anything, it just beeps and then the power light turn off.

Try each memory module by itself in each socket until you isolate the bad module or the bad socket.  If one module works in either socket, and the other doesn't, replace the bad module.  If neither module works in one socket but does in the other, it's the socket that's bad;  replace the mainboard.   If you get no results doing this, it's the mainboard that's bad.