Audio Systems: Stereo Receiver-Internal Power Supply, sony stereo, stereo receiver

Question
I have an older Sony Stereo receiver. It will work for about 5 minutes but then the audio cuts off but the receiver is still on, display is lit? Took it in and they said needs a new Internal Power Supply for $150. Does this sound correct...fair price...should I just buy a new one? I don't need anything too fancy, just a basic receiver.
Thanks for your help.
Bob

Answer
Withoput knowing the model, I can only provide generalities.  I am not aware of any Sony that has an "internal" power supply that would be a replacable unit.  Ususlly the power supply is component repaired if it has failed.  Please update this with the model number and I might be able to provide details.
Dan