How to confirm if your unmanaged switch is faulty?

Step 1 : Remove the switch from the network and isolate it.

Step 2: Have the switch powered off for 5 to 10 minutes with absolutely no Ethernet or power cable connected.

Step 3: Now power on the switch and Connect 2 PC's to it which are assigned static IPs in same subnet with same subnet mask and with DNS and Gateway information left blank.

Step 4: Disable Firewall and antivirus on both the devices and then try to do a continous ping them from each other.

Step 5: Repeat the ping by shifting the PC to different ports randomly.

Step 6: If the ping between the PC's failed on any/all the ports the switch is diagnosed to be faulty and you have to contact the manufacturer for warranty based replacement.

Below is just a illustration of how the connection during test should be.