Tandberg Unit needing some love


Hello Everyone,
I write this for a very good friend who has a Tandberg 1055 unit that has low pre amp output on one channel. This is a unit that is about 40 years old. He with my help is looking for someone with knowledge and skills to repair it. He resides in the 07764 zip but of course can ship the unit. We have tried several leads but come up empty.
Thank you for your time and anticipated help   
wmwman
Why would it be? Electronics from that age is usually designed with many discrete and freely available components. If one of those has failed, it will be easy to repair.
Thank you williwmj !   I hope for his sake it is easy.... He actually was recommended a repair facility some what near him by a high end installer and when he contacted them they were not  even aware of the name Tandberg. Anyway, I appreciate the input.
Why would it be? Electronics from that age is usually designed with many discrete and freely available components. If one of those has failed, it will be easy to repair.
+1