Firstly disassemble your calculator from any screws located in the back, accessing the internal components

Find the display supports or the PCB supports that are broken, damaged or lose. After aligning properly the display, if your PCB / display supports use screws, tighten the screws holding the board or display, else if clips are being used, use super glue to hold the PCB / display down into place, and wait for the glue to dry .

Check out step 3 ( optional ) . Lastly, close up your device, and you're ready to go!

For your safety :‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎⦿ ‎ ‎ If your calculator has a VFD display or uses nixie tubes, disconnect from power and discharge properly any capacitors.