I have a discontinued 1232 analog system that is experiencing randomly, it will stop running. Upon arrival, I notice that the Power Supply and the voltage regulator are very warm to hot. If I power down and up, solves the problem until another day. I have replace the whole cabinet and Power Supply and regulator. Any suggestions. Could it be a a circuit board loading down the PS.

What's is the exact model # ?
Are we talking about a 1232-10 or 123211D ?
It could be the voltage coming in also.
Is it properly ventilated ? it may be loaded with dust and needs a good cleaning, (on the inside) I would try a good UPS with true automatic voltage regulation.
You can still get parts for those old units but you would probably be better off replacing the control with a KX-TA 624.
The ups is a good investment regardles as you can always use it on a new control.
I would try a good cleaning and a UPS with AVR.

System is alanolg not digital.

Enviroment not an issue. Office area.

Put a good UPS on it, one with true AVR.
If that doesn't do it then change it.