96 lumina,does'nt shift into gears-HELP!!

Hi, my lumina wont shift into gears anymore, have disconnected battery, unplugged the puter, changed filter,screen fluid. nothing, here's what it did before hand, you had to rev the engine to get it to shift towards the end, the fluid was a little brownish but not bad, the pan was fine, tried some seafoam trans stuff but that only worked for a while. someone told me it could be the solienoid, i have another but what a pain to change. don't know if its the clutch shot in it or something electronic, you can see the gear lever moving but nothing happens, please post h ere or at shur10k@yahoo.com.