Problems with noise, heat bed temperature and no X / Y endstop sensor on Makerbot Replicator 2X

I bought a used Makerbot Replicator 2X, and I have some problems printing with it. The first problem I run into is the first layer adhesion to the print bed, it seems like the temperature of the bed starts to drop directly after first heating it.

Also, calibration seems to be a problem, because when using the Home Axes function, the extruder is moved to its home – but there seems to be like a missing endstop sensor, because the stepper motors starts making a whole lot of noise.

Also, when moving the extruder manually using the Jog function, there is a lot of noise and also it’s possible to move it out of its range (same type of noise as with the Home Axes function).

I understand that the bot I bought is not to be expected to function as new, but I need to understand what the problem is and how I can fix it. Is there parts missing even?

Trying the Home Axes and Jog functions resulting in a lot of noise: https://photos.app.goo.gl/j3HX9qHvZCEBnPru7

Printing with no adhesion and a falling Platform temperature: https://photos.app.goo.gl/PHVtheWCRRmhz7bu7