@jashie 

Hey

The 169.x.x.x IPs are likely caused by APIPA (automatic private ip addressing), in short its a backup address used when the device isnt getting a valid IP address from the server (router in your case)

It could simply be the switch is gone, but thats not really that common.   I would test this first by statically setting 2x of the stations with IPs.  Say  192.168.1.2 and 192.168.1.3 and see if they can ping eachother via the switch, this would indicate that the switch is working.

You are then looking at the router or DHCP as an issue.

You cant reset the TL-SG116 as it doesnt store anything, it just chucks one port to another.  There is nothing to reset par say

Thanks for the reply. Strange things are happening. If I connect a device (PC) to the router no problem, if I connect the same device via the TP-SG116 the main router disconnects the WAN from the Internet. Unplug and redirect to the router and WAN restores itself.  Not sure why... I guess I have some troubleshooting to do.

  @jashie 

Yeah deffo some troubleshooting.. 

Try setting a static address and default gateway on the PC, connect it to the switch and the switch to the router.   See if it works using static addresses..   if not, then it could be a failing switch sadly

Not that common for switches to fail, but does happen!