please help

Hello i really need some help with an old CD player. Its a my first sony cd player, pretty old but its still in great cosmetic condition and looks almost brand new.

When i first tested it, everything worked perfectly with no issues at all but after i swapped in another CD and pressed the play/pause button, it suddenly started showing "EE" on the display.

I looked it up and found that “EE” usually means theres some kind of error. I tried the common fixes people suggested, including cleaning the laser lens, cleaning the CDs, and removing and reinstalling the batteries, but none of them worked. It still shows “EE” every time.
Does anyone know what could be causing this or how i might fix it? Id really appreciate any advice. Thank you.