onkyo receiver lost surround channels, whats up? Please help

Ok i had a Onkyo tx-sv727 for about 6-7 years and about a year ago sold it to my wifes brother, well basically gave it to him, anyway.... he lived with a roomate and so never hooked it up, (basically bought because of the steal he got) for when he got his own house. Ok so now we are a year later almost, its been sitting in his room and now has a place of his own and i went saturday to hook it up for him,

The receiver worked great when i gave it to him, unhooked it and replaced it with my Integra receiver,

Of course now the center and rear surrounds won't come on, not even with the test tone, also when you screw down the wires on the back with the binding post the fronts "That work" try to cut out or make static noise alittle... I feel like a heal and that it seems i sold a piece of junk, although it worked great when i sold it.. He said don't worry about it.

Ok what can this be "the short version please"
Could i get some rat shack tuner cleaner and compressed air and try that on the terminals inside where the binding post are attached??

I really want to know if this could be from sitting unpowered for a year?? the case had alot of dust on it and the remote was sitting on it and was covered with dust also.. So i can say dust could be a problem maybe???? Let me know so i can help him out