2004 Peugeot 407 indicators have stopped working?

Peugeot 407 - year 2004 - switch Valeo COM2003
The indicators are not working but the hazards work.
The stalk seems to be in order, and I believe I can hear the switch activate when moved fro LH to RH. I am sure the agents have not tested the switch, but they want to replace it at a huge cost. Has anyone got a method to check the unit, or knows another reason why the indicators may not be working