Double check that it's parking the heads in the right position, fully capped,
and that the pump is working. If either of those are wrong no amount of head
cleanings will work. If they are correct:
Disconnect your bulk system and hook up a syringe to the line(s) of the clogged head.
Gently, very gently, squeeze some fluid (ink, water, windex, doesn't matter) into the
line. Do not push hard.
Epson's get testy when it gets warm and dry out.