Hi 9999999helpme,
4 Beeps indicates Memory/RAM failure on the computer. Try to reseat the memory on the computer.
Also, check with each memory module and Power on the computer.
From the above link click Manual and Documentation and click Service manual to access Memory reseat/remove section.
Before Opening the chassis, I recommend you to remove the battery and disconnect the adapter, press and hold the power button for few seconds and release to drain the flea power.
Note: Reseat the memory if you are comfortable in doing so.
** NOTE: Please ensure that the power cable of the computer is disconnected before opening the chassis. Refer to the Service Manual for assistance on removing or replacing the internal components of the computer.
Awaiting your response!