Hub3 connection to unmanaged Ethernet switch

[Grintstick]

Hi - I have a hub3 - connected to the Ethernet ports are:

- my Samsung tv

- A TP link unmanaged switch.   This switch then feeds a max laptop and a pc.

problem is - whenever I connect the unmanaged switch, it knocks out the connection to the Samsung tv.   Weird eh?  
Also - the connection to the pc from the unmanaged switch only works if the Mac laptop is also connected over Ethernet - again, strange behaviour?   Taking the switch out of the equation restores connections. 

if just replace the switch, but had the same issue with a previous net gear switch.  Is there anything in the Hub3 that could be causing this? 

thanks! 

[Roger_Gooner]

Do you need a switch for only three devices?

Also is the hub in router or modem mode.

[Client62]

I'd suspect the network cables between the Hub and also the Switch and the PC + MAC.
Replace all of the network cables & see if the issue clears.

[Grintstick]

Trouble is - the devices plugged into the switch are mikes away from the router so I don’t want to run more cables than needed. 
Hub is in router mode.

thanks for the reply. 

[carl_pearce]

You need to test the cables as that appears to be the only common item not checked, other than the HUB being faulty, which doesn't really make sense at this stage.

[Grintstick]

I’ve actually done that already - suspected it was Ethernet cables, but no joy!

[Client62]

How were the network cables tested ?

[Grintstick]

They were replaced with new ones rather than tested. 

[Roger_Gooner]

Replace the switch, it rarely goes wrong but it happens sometimes.

[carl_pearce]

They've had the same issue with two switches, of different brands, so odd, no?