starter repair??

my starter on my 92 crown vic(4.6) isn't working,no power or nothing on the tester at autozone,have had the main body apart and everything looks fine,plenty of brushs left,all wirering is intact and not burned,gears look fine and nothing chipped or broken, how do you test if poosible the solinoid on it,i'm guessing there isn't any power to the starter from the solinoid,autozone tells me you have to replace entire starter(over $100)there's got to be a way to test just solinoid? also as long as the starter is apart-is it a good idea to clean parts (gears and shafts)and inside of housing,magnet field,etc, with carb cleaner,brake cleaner or electric spray cleaner providing solinoid is problem and can be replaced??