OK, here goes...I have an old hot tub probably 1986 or so. It was built by my late Father in Law when he was working a at hot tub manufactuerer that is no longer in business. The tub was a grade 'B', if that matters. Anyway, the problem is that after burning up the old control panel over a year ago we are now attempting to install a new panel (same model) it's a FF-2000-6K-LTC1 manufacturered by Len Gordon. We think we have it hooked up properly but the system doesn't turn on. There is a magnetic switch that we don't have hooked up, because we can't find where it goes. Question 1 is would this stop everything from working? Question 2 is if yes to question 1 then where do we connect the magnetic switch up at?

Any assistance will be greatly appreciated...if you email me a phone number I will gladly call you. Thanks

magnetic switches are usually door interlocks so that if the access door in the spa cabinet is opened or removed the system is shutdown for safety.
you may find the magnet on the door, if not you can bypass this system by shorting it out or placing any magnet on the switch - tape it to it.

Most new spa packs will have a door interlock, and since you don't have yours hooked up, it could very well be the reason your spa will not function at all. As for location of this connection, I can't say without seeing the board. If you could, please post a high resolution (max filesize 250Kb) photo of your board, so I can perhaps locate this connection for you.