So we just bought the TS-433, when we plug it to the Switch, it color turn from orange to green.
Then we use our computer under the direct LAN Network, same network & ISP, but different floor.
It failed to detect to recognize the NAS, and also when we try to install the QTS, the file seems unable to open the file (unrecognize)
I am using TS-251D QNAP and tried to install from scratch everything. The 5.2.3.3006 must have some problems inside since always the installation stops at 10% or 11%. Restart happened and again Smart Install was lunched. I cannot login using QFinder to change firmware but the QFinder showed the device. I tried to install by web but also failed. The status LED is ON (green), no network LED, and the drives led are quickly flashing together. I have been waiting for 30 minutes and nothing changed (2 x 4TB NAS HDD).
I had to reinstall DOM, returned to basics, install version 4.5.4 and it started…
The I tried upgrade to 5.x and again system hangs 
Yeah, I did install that one and fail
When you can’t find your NAS, you have a network problem.
Find your router the NAS ?
Which IP has your NAS become from the router ?
Can you log in with your browser “192.xx.xx.xx:8080”
I see, I will try to use Switch in my next attempt so that the network is closer and have the same network
After I bought & Install it, it still can’t detect the NAS system
Your NAS received the IP from the router in your network.
I have a fritzbox as router. This router is the DHCP-server for my network. This server give my NAS the IP.
Your switch is no DHCP-server.
