I agree with what Glen said above. Most folks that would work on that would charge more than what the unit is really worth. That rig uses switched low pass filtering and switched band pass filtering. These switching networks become intermittent which can causes loss or decreased receive due to contaminated contacts. Sometimes cleaning them with DeoxIT will restore them
Sit down with the rig, a multimeter and a schematic. Explore the board. See where voltage is present--and where it isn't. It's an interesting exercise and it might help you isolate the problem.
