Tiagra Dual Control Shifter not working

georgemonkey
georgemonkey Posts: 11
edited June 2011 in The workshop
My rear gear shifter has stopped working. It will not pull the cable. When I tried with the cale disconnected from the derailleur, it will only click four or five times. As it clicks, it is not pulling the cable at all. The indicator line on the hoods suggests it has only clicked halfway through the sequence. Any suggestions?