How can I downgrade my SGH-I527M from 4.4.2 to 4.2.2 topic

When I flash a rooted 4.4.2 ROM and BL , I upgrade to I527MVLUCNE5 but my phone touch panel doesn't work.
So I flash back to I527MVLUBNA3 , then I got a unknown baseband version and have no wifi & bluetooth & mobile network signal.
How can I restore my phone to a usable status?