The problem can be a number of things. Sometimes it can as simple as cleaning the unit. Relay's and potentiometers are common issues with older gear. Could be be a bad solder, a cap etc.

If you decide to get it serviced, let us know what was wrong with it. If not, there is great interest/demand by many audio enthusiasts for vintage electronics. I'm sure you can find someone to buy it off of you cheap and they will fix it up.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne