LM3509: no output on the OVP and SW pins

Hello,

a few days ago I've received my new PCB with LM3509 on it which supposed to drive 6 white LEDs (3 x 2). After assembly and tests all component on the PCB work apart from the aforementioned LM3509. I've been trying to debug the issue with no luck. Basically, it doesn't produce anything on the OVP output. I connected an electronic load (DL3021) to see if it draws 18 mA - dead. Then, I looked with a scope if there is any signal on the SW pin - dead, nothing, no movement at all. 

I looked at the design countless times - it follows the datasheet. So, I don't know where the issue may lie. Thus, if you could point me into the right direction where to check or if you see an obvious mistake in the design which I am too blind or ignorant to see, I would really appreciate it! Below are Schematics, Layout images and BOM.

BOM:

Kind Regards,

Den