Problems with the bed and the screen - Anycubic i3 Mega

Good afternoon,


I have an anycubic i3 mega for 2 years ago and although it has been going well lately it has many problems.


There are two problems:


- The bed becomes very loose during printing, so much so that even the screws fall off. Obviously for the quality of the print it is terrible and it is to the point that in short prints it works more or less well (although I have to calibrate it yes or yes before printing), but in long prints it can be de-leveled 2 mm perfectly. The glass of the bed is new but the screws, the metal base, the springs, etc., are the original ones.


-The screen clicks alone. When the printer is turned on it works well but when heating the extruder for example, it starts to click by itself (you hear the typical noise too) and it is impossible to start printing.


Let's see if you can help me, thanks!