I have a Schwinn with a shimano 105 set. I have not ridden the bike in a year or two, so I give it a wash and put on a new chain. I then give it a test ride and it would only down shift on the rear. That is, it would only move to a smaller cog, and would not move to any larger cogs. Now, it won't shift at all. When I click the shift lever I don't feel any significant change in tension in the cable, and the derailleur doesn't move at all.

I'm also getting the same problem with the front derailleur. It won't shift. Although I can feel the cable tension change a bit when the shift lever is actuated, which is more than I can say for the rear derailleur.

Any suggestions on where to start?

Thanks