In theory yes, depends on difference between "freeview ready" and "freeview built in". I think that freeview ready just literally means the set can receive digital signals, and a separate digi box is needed, if it's built in the set has the encoder built in so setting it up and tuning it is a...
Try to isolate the problem. Bypass the splitter and plug a tv straight into the aerial feed, and try different TVs from different ports on the splitter. That way you can isolate problems. Are the TV(s) downstairs working? try all the combinations and you can narrow the problem down.
The other...